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-   -   Securing a safe to a post-tensioned slab - DIY (https://www.calguns.net/calgunforum/showthread.php?t=731447)

John Browning 03-24-2013 3:21 PM

Securing a safe to a post-tensioned slab - DIY
 
If you have a post-tensioned slab, you cannot drill straight into it to bolt down your safe. I need to be clear that you should never, ever, ever, ever drill a PT slab on your own. You risk serious injury, death and structural compromise. No rational contractor will advise you to drill a PT slab without GPR or x-ray, and that costs much more than this project. However, you can still bolt it down using this simple do-it-yourself primer.

At each step, double check all your measurements, making sure that things are square, level and right. It is very hard to undo mistakes, so get it right the first time.

First, how can I tell if I have a PT slab?

LET ME BE CLEAR, If you are not sure that you have a PT slab, stop. Ask a professional before you drill. NEVER EVER DRILL A PT SLAB. I CANNOT STRESS THIS ENOUGH. Do not rely on your slab being stamped. Many are marked in the garage, and many are not. You can look at the outside of your slab if you are not sure. There will be grouted holes 3 to 4 inches in diameter every 3 feet or so. The best way to tell if you have a PT slab is to look for these holes, and look at a side where there is no concrete poured next to the foundation and the top 12in of the slab are visible. Do not rely on the slab being stamped as PT. If you think you might have a PT slab and don't want to ask a pro, then assume it is a PT slab.

I took these photos for two reasons. One is to help you guys. Two, if I ever have questions on what is underneath this slab, I have proof I never drilled it. If I were you, I would document this project as a CYA.

Step 1: Go to USPS and pick up a change of address packet. This has a coupon for 10% off your entire purchase at Lowe's. Home Depot will also take this coupon. You can save 10% on your safe and everything else, so buy everything you need in one swoop. The coupon used to be instant, but some now apparently require registration and take a few days to arrive via email.

http://i41.photobucket.com/albums/e2...ps73bb781a.jpg


Step 2:
Plan your shopping list.

Here are the things I used for this project:

2x6 for forms
2x4 to screed
Sakrete
Portland cement
#4 rebar
Wedge anchors 5/8 - 6in
concrete edge and finishing tools
Skilsaw w/ wood and masonry blades
Sawzall w/ metal blade
Drill w/ Phillips driver, 3/4 Metal bit, 5/8 Masonry bit
Wheelbarrow
Sika LatexR Concrete Adhesive
Level
Wedges to level
Doobie blocks
3 in screws or concrete form nails
Respirator
Safety glasses
Extension cord

Then go to Home Depot (they have more of this stuff) or Lowe's and buy everything you need. Remember, you can buy your safe at the same time and get 10% off with the coupon.

http://i41.photobucket.com/albums/e2...psbcef2022.jpg

http://i41.photobucket.com/albums/e2...ps339da7b8.jpg

Step 3: You'll want a diagram of the anchor hole dimensions of your safe if you are ordering it like me. I called AMSEC and the emailed me a diagram of their HS safes in a few minutes. If you buy it at HD, you can just measure it. You will want to sketch out the dimensions of your new housekeeping pad. I sketched mine out several times to get an idea of where I wanted it. My new safe is 40w by 26d. I made my slab 45x30 because those are great calibers, and because you want to be 4-6in larger than your safe. I"d go larger, but that would extend too far into my garage. Anyway, just sketch out what works for you. I went through a few different sketches before I figured out how large I could go and not be intruding on too much garage space. The bigger you can go, the better, but everything in life is a compromise.

http://i41.photobucket.com/albums/e2...ps7631b5f4.jpg

Step 4: Once you have your area sketched out, you need to scuff the slab. This will allow the new concrete to better adhere to the old stuff.

Before you start, you NEED a respirator. This step will create a ton of concrete dust, so empty out the garage and cover what you can. Then, eyes, ears and respirator on.

I used a masonry blade on my Skilsaw and a FatMax Fubar to do the job. I gouged the slab with the Fubar and dragged the masonry blade at a 45 degree setting across the concrete. Ideally you want to scuff the entire area of the slab, but I wound up going a few inches less than that. Remember, you just need to scuff the surface, not go deep. You can also use an angle grinder to scuff up the slab.

Once the slab is scuffed up, make sure and get it cleaned off. Dust will severely weaken the bond, so get it as dust free as you can.

http://i41.photobucket.com/albums/e2...psdaca5c14.jpg

Step 5: Once you have the slab scuffed, you can set your forms. I won't go into how to do this as there is a ton of info out there on it, but just make sure that you have them level and secure. I secured mine to a workbench and then directly to the wall. A proper slab will not be perfectly level so that water drains out, so don't just set yours on the slab and go. You will need to level it out.

http://i41.photobucket.com/albums/e2...pse836664e.jpg

At each step, double check all your measurements. Just reminding you. :)

Step 6: Now it is time to put in your rebar. This is where knowing the anchor hole locations is important. Put in the rebar on top of the doobie blocks so that you are certain to avoid the anchor hole locations. THIS IS CRITICAL. Once you are certain that the rebar is nowhere near where you are going to set your anchors, check your forms and your measurements again.

http://i41.photobucket.com/albums/e2...ps81b3a4b5.jpg

John Browning 03-24-2013 3:23 PM

Step 7: Double check everything. Check that the forms are level and secure and that the rebar is not going to be in the way of the anchor holes.

http://i41.photobucket.com/albums/e2...psee159256.jpg

Step 8: Now you are ready to mix and pour the concrete. The only special step you need to take here is to take the SikaDur LatexR Concrete Adhesive and make a slurry to put down. The directions are on the bottle.

Then take the rest of the Sika and mix it in with your first batch of concrete. I mixed mine in a wheelbarrow. adding a 1/4 a bag of Portland Cement to each bag of Sakrete High Strength concrete. You don't want it to be too wet, and it needs to be well mixed. Then just dump it into the form. If you're not sure how to work and finish concrete, there are a ton of DIY primers online.

Finish the slab, and once it is cured you can pull the forms. Now you've got a slab that you can bolt your safe down to. See the DIY sticky on how to bolt down a safe and go for it.

http://i41.photobucket.com/albums/e2...ps301e7c78.jpg

Step 9: Optional extra safe straps

Once your safe is bolted down, it is probably not going anywhere. The weakest link in the chain is most likely the bottom of the safe, which will probably be ripped off before the bolts shear or the slab moves. To reinforce that, here is what I do.

My last safe came with 10 gauge steel supports instead of a pallet. I take these, and drill two 3/4 in holes spaced correctly for my safe. Then I use these below the washers and nuts on the redheads to reinforce the bottom of the safe.

On the left is what it looks like before, and on the right is after. Then I take a sawzall and cut the side off and cut it to length if needed. On a side note, this is the same steel used in most of those low-end Winchester/Canon/Browning/Cabelas/Stack-on/AMSEC safes. You'd be amazed how quickly a Sawzall can chop through them.

On another DIY, I'll show you how to turn a $1000 safe into a much more secure container.

http://i41.photobucket.com/albums/e2...psfb0d8f73.jpg

Anyway, I hope that this helps.

John Browning 03-25-2013 12:00 PM

Quote:

Originally Posted by nephrodoc (Post 10903960)
Brilliant idea for a garage install. I had to put my safe inside, did not bolt down though because of the post tension slab.

Thanks. I am hoping this will get a sticky because safes really need to be secured. A lot of people think that because you have a PT slab you can't bolt it down and it has to be weakly secured. That is not the case. The slab I added will weigh about 600 pounds and with the adhesive you would need a winch and a F450 to pull it out. Making the slab larger than the safe also adds another lever arm that makes the safe harder to move. Best of all, this project only uses about $100 in materials if you already have the tools.

I am making sure my safes are all secured to where they can't come out. I have a friend in our development (also with a PT slab) who had a safe, and it was broken into with a crowbar. Now her safe was crap, but even then they made the effort to pull it out and get it on its back. It was lagged into the plywood subflooring and came out easy.

This housekeeping slab is the way to go if you want to take your safe with you if you move. I'm putting a very, very expensive safe here and don't want to leave it if I move. I'll be doing another DIY project with a much less expensive safe showing how to secure a safe to a PT slab if you really plan to keep it with the house.

John Browning 03-25-2013 2:23 PM

Quote:

Originally Posted by Ninety (Post 10910987)
Should be a stamp.. ^^

But OP are you saying that you cannot drill into a post tension slab? Or you can't drill into a tension cable on a post tension slab? ..which are pretty hard to cut with a mason drill bit... they will bounce off and you will know you hit one... Just x-ray it and don't drill the cables. :shrug:

But nice write up and not a bad Idea at all.. looking forward to your safe re-enforcement write up.

Drilling a PT slab should never be done unless you've had the slab x-rayed, and since a slab x-ray costs a pretty penny, I'd never drill one. That is after 20 years of construction experience and years working with concrete and PT.

Those cables are stressed to a degree that hitting them with a masonry bit won't cut them, but it will snap them. It isn't like hitting rebar. The tension in the cables makes them want to fly apart as soon as they are hit. More importantly, drilling a PT slab will void your home warranty, and if you hit a cable you're looking at a five figure repair bill.

The risks of drilling a PT slab are enormous, and the effort it takes to solve the problem is a full day project at best with minimal cost. Seems like a no-brainer to me.

paul0660 03-25-2013 2:38 PM

drilling a two inch deep hole in any concrete is going to snap a tendon as often as airliners having a head on. Use epoxy to secure the anchors, not redheads.

Too much rebar, too many dobies (they create a void). Mesh pulled up to the middle of the pour would have been ten times better.

But, a good training project for sure.

John Browning 03-25-2013 3:57 PM

Quote:

Originally Posted by paul0660 (Post 10912269)
drilling a two inch deep hole in any concrete is going to snap a tendon as often as airliners having a head on. Use epoxy to secure the anchors, not redheads.

Too much rebar, too many dobies (they create a void). Mesh pulled up to the middle of the pour would have been ten times better.

But, a good training project for sure.

Mesh is a terrible choice for such a small slab, but whatever. I could use Epcon or Hilti Epoxy, but the bottom of the safe will rip off long before the redheads give, so no need to epoxy a safe.

Only a moron drills a PT slab.

paul0660 03-25-2013 4:01 PM

Quote:

Only a moron drills a PT slab.
Well ok, but I didn't spend 20 years overbuilding stuff because I couldn't figure out how it was made in the first place, as you apparently did, and didn't. Most of the people reading this probably have an appreciation for the facts, what their time is worth, etc.

John Browning 03-25-2013 4:12 PM

Quote:

Originally Posted by paul0660 (Post 10913093)
Well ok, but I didn't spend 20 years overbuilding stuff because I couldn't figure out how it was made in the first place, as you apparently did, and didn't. Most of the people reading this probably have an appreciation for the facts, what their time is worth, etc.

I now appreciate air conditioning in the summers and a five minute commute so construction is no longer my thing, but I still have a General Contractors license in both CA and NV. Your resume?

Yes, this slab is totally overbuilt if it were a driveway or a sidewalk or some other regular slab. However, the overbuilt part of it ran me about $4, and the extra strength in the slab makes that $4 well spent.

John Browning 03-25-2013 4:53 PM

Quote:

Originally Posted by paul0660 (Post 10913239)
Yeah you could park your pickup on it if it would fit.

My resume is a dozen building projects and getting generals and subs to not rip me off, no matter how smart they act, and 3 lawsuits that I won.

I mentioned epoxy because half the time noobs will rip the red head hole up by over tightening.

I offered an alternative because I know how post tensioned slabs are constructed. They aren't hand grenades, and the tendons are not within two inches of the surface, which is why I noted that dimension.

Seeya!

So, in other words, your only contribution here is to offer nothing. The only thing you did mention, to look for a stamp, is also wrong. My home is not marked anywhere, and many homes with PT slabs are not marked. We'll get to that later.

A 2in hole in a PT slab voids a home warranty for most people. That is very bad. Generally those tendons are 2in from the surface, but they don't always run parallel to the surface so you can absolutely hit one at less than 2in. That alone would be a reason to never drill a PT slab. Even if you were to drill a 2in hole and miss a tendon, a 2in epoxy anchor offers virtually no strength. A 2in hole with epoxy offers less than 1/8th the strength of a 6in hole, and the force requred to pull the anchors is less than the weight of a decent mid-level safe.

A real contractor will get an x-ray or use GPR before they ever drill a PT slab. If you want to go ghetto, mess up your life DIY like you're suggesting, here is some factual info to digest.

LET ME BE CLEAR, AS A LICENSED CONTRACTOR, ONLY A TOTAL MORON DRILLS THEIR OWN PT SLAB. NEVER EVER DRILL A PT SLAB. I CANNOT STRESS THIS ENOUGH. If you're still wanting to drill a PT slab, this is what a very stupid hypothetical contractor would do. I am not advising anyone to do this, because it is very stupid. Despite any reasonable professional advice to avoid it, he would look at the outside of your slab. There will be grouted holes 3 to 4 inches in diameter every 3 feet or so. The best way to tell if you have a PT slab is to look for these holes, and look at a side where there is no concrete poured next to the foundation. Do not rely on the slab being stamped as PT. He would guess where the cables run and drill, which is stupid. PT cables will be covered typically in a red plastic, so if he drilled it and hit plastic, he would stop what he is doing and then drive away, leaving you with a big problem. He probably had no idea that is the case, though, so when he hits the plastic, he keeps going until he snaps the cable. Then he realizes something is wrong, packs up his tools, and drives away hoping you don't have his information to track him down. That is why you don't do this yourself or hire very stupid contractors.

The tendon anchors are under 10,000-30,000 pounds of stress in most residential slabs. If you hit a tendon, they fly apart like something under 30,000 pounds of stress, which is violentlly. The anchors can (and do) fly a few hundred feet and people have been killed by drilling PT slabs. Smart people don't drill them ever on their own, and professional contractors will not drill them without x-ray or GPR.

If you don't mind ruining your foundation and killing yourself or someone else in pursuit of a 2in hole that offers no support, take paul0660's advice. Make it clear to your attorney that it was paul0660 offering that advice, and that I advised against it when you want to file your lawsuit. If you want to have a safe bolted to a PT slab, do what I said above which is to create your own housekeeping slab that you can drill and not worry about. Do not drill a PT slab. You can listen to a licensed contractor talking the talk and then walking it, or some internet certified keyboard expert. It is your house.

Here is a nice video showing what happens when just one PT cable fails.


John Browning 03-25-2013 5:44 PM

Quote:

Originally Posted by nephrodoc (Post 10913820)
Yes, I also inquired about drilling in my PT slab. I was told it would void my home warranty, possibly my homeowners insurance as well. I already have a hard enough time finding homeowners insurance due to my high fire risk.

The only option was to get a licensed company to mark the tendons with X-ray. Not worth the risk or hassle in my opinion.

If you had literally nothing, you could honestly do this project with hand tools and have the whole thing finished for under $150 easy buying the essential tools. You could almost certainly borrow the essential tools and be done for less than $50 if you are in a pinch. Definitely not worth the risk or hassle.

John Browning 03-25-2013 8:03 PM

Quote:

Originally Posted by mike_c70 (Post 10915292)
scobun - sidetracking a little bit. I have a newer built home (2004). I don't remember if it has a PTS, don't remember seeing any markings since I coated the whole garage floor. Would city hall be able to check what kind of foundation my home has? Foundations go through inspections right?

The foundation has been inspected many times, but I don't know that many cities keep records of the inspections. The markings on the garage are usually stamped into the concrete, but like I said before, mine is a PT slab and is not marked anywhere. If you're not sure, have a contractor buddy take a peek at it. If you're in a subdivision, see if any of your neighbors know what their slabs are. Most tracts that have PT slabs have them on most of the homes. You can also look for the grouted 3in holes every three feet on exposed slab.

damngato 03-26-2013 7:38 AM

Thank you very much for this DIY! I have the PT slab and thought I was SOL as far as bolting it down. This looks like my next project. When you talked about a proper slab not being completely level you were talking about the existing floor, correct? So we need to take that into account when we make our new slab is what I got out of that. Just wanted to double check.

On a side note, I'm not home but I know the garage has the stamp but we also have an outside patio area which was there when we moved in. Would that usually be the same PT slab? I'll look for the holes when I get home but just curious. Thanks again for the great info!

John Browning 03-26-2013 11:57 AM

Quote:

Originally Posted by damngato (Post 10918525)
Thank you very much for this DIY! I have the PT slab and thought I was SOL as far as bolting it down. This looks like my next project. When you talked about a proper slab not being completely level you were talking about the existing floor, correct? So we need to take that into account when we make our new slab is what I got out of that. Just wanted to double check.

On a side note, I'm not home but I know the garage has the stamp but we also have an outside patio area which was there when we moved in. Would that usually be the same PT slab? I'll look for the holes when I get home but just curious. Thanks again for the great info!

Correct, the existing garage slab floor should have a very slight grade to it.

All exterior residential concrete like driveways and patios that I've ever seen are just standard rebar. I would doubt that they are PT. I'm glad you found it helpful, that is what I was hoping for.

odysseus 03-26-2013 12:01 PM

I also want to note for post-tensioned slabs that if you drill into the slab - and avoid the tension cables, and yes void the warranty and such, if you later try to sell the house - you can get hit by prospective buyers on inspection with this. They can try to dock you on the asking price with the cost of fixing that. It is not going to help the sale, is what I mean to say. Of course, they might not be happy with the extra concrete work as noted here, but that is not a point against structural integrity.

John Browning 03-28-2013 1:40 PM

Quote:

Originally Posted by odysseus (Post 10920921)
I also want to note for post-tensioned slabs that if you drill into the slab - and avoid the tension cables, and yes void the warranty and such, if you later try to sell the house - you can get hit by prospective buyers on inspection with this. They can try to dock you on the asking price with the cost of fixing that. It is not going to help the sale, is what I mean to say. Of course, they might not be happy with the extra concrete work as noted here, but that is not a point against structural integrity.

Good point, and another good reason to have photo evidence of what you did.

Also, when you drill for the anchors, make sure and drill a hole that is less than the depth of your new slab. Redheads sunk at 4in require something like 6,000-8,000 pounds of force to pull, so no need to drill the hole to China or into the PT slab.

John Browning 03-29-2013 6:39 AM

Quote:

Originally Posted by Rider1k (Post 10945692)
all good info. I would drill at least four 5/8" holes equal distant inside your forms and epoxy 5/8" all thread into them. When the epoxy is set I would either tie these to your rebar grid for the pour or better yet even lay them out so that they mate with the holes in the floor of your safe. Bolt your safe to these with a washer and nut any it isn't moving!

My safe is too heavy to make this practical when it comes to setting it in place, and I didn't have it here so I didn't want to run the risk of being 1/16 off. For me, the safe had to be set on the slab and then drilled.

If I had a lighter safe already here, your method would be the best by far to secure it down.

1911Luvr 03-30-2013 11:17 PM

I'm glad I read this- I called Boswell Safe about installing mine with bolt down service and they said they could drill down to 2 inches in my PTS. I'm going the slab route now, thanks!

UPDATE: see the finished pics on page 2

Librarian 04-07-2013 5:28 PM

Cleaned up.

If anyone -really- wants a post back, none of them are GONE gone - I can bring one or two back.

Generally ask a question, quote the question in the answer, allows the original question to be deleted.

John Browning 04-07-2013 7:54 PM

Thank you Librarian.

TANK 05-05-2013 8:15 AM

good write up, thanks for the info

L.A. Saiga 06-25-2013 3:22 PM

this is great info. thank you

Speedpower 07-25-2013 6:57 PM

Quote:

Originally Posted by scobun (Post 10920872)
Correct, the existing garage slab floor should have a very slight grade to it.

All exterior residential concrete like driveways and patios that I've ever seen are just standard rebar. I would doubt that they are PT. I'm glad you found it helpful, that is what I was hoping for.

Now that I just found out too that my concrete floor inside the house is also a PT slab (as it was stamped in the garage floor) what other way can I do to bolt down my safe, I don't want my safe in the garage, I want my safe inside the house, how do I secure my safe? I mean what is the best way? ideas please?

sd_shooter 07-25-2013 7:59 PM

Quote:

Originally Posted by Speedpower (Post 11910381)
Now that I just found out too that my concrete floor inside the house is also a PT slab (as it was stamped in the garage floor) what other way can I do to bolt down my safe, I don't want my safe in the garage, I want my safe inside the house, how do I secure my safe? I mean what is the best way? ideas please?

Why don't you secure it to a couple wall studs using lab bolts? Put the safe in a closet and figure out where the studs are. Drill through the back of the safe (not hard with your typical Costco/HD/Lowes safe...) and voila - just as much of a PITA for the bad guys as through it were bolted down.

And BTW, they'll still get in there if they have the time and tools for it. Bolting it only slows them down.

Speedpower 07-25-2013 8:09 PM

Quote:

Originally Posted by sd_shooter (Post 11910922)
Why don't you secure it to a couple wall studs using lab bolts? Put the safe in a closet and figure out where the studs are. Drill through the back of the safe (not hard with your typical Costco/HD/Lowes safe...) and voila - just as much of a PITA for the bad guys as through it were bolted down.

And BTW, they'll still get in there if they have the time and tools for it. Bolting it only slows them down.

I was thinking about drilling the back but
i have an inch gap in between the safe and the wall, do I fill the gap with a piece of wood then bolt it through to the stud? then wouldn't it void the warranty of the safe by drillingthe back side? anyway it's funny that people say that it's better to have a safe than not having a safe, now that I have a safe, I still have a problem

jeffme 08-19-2013 1:58 PM

Quote:

Originally Posted by scobun (Post 10920872)
Correct, the existing garage slab floor should have a very slight grade to it.

All exterior residential concrete like driveways and patios that I've ever seen are just standard rebar. I would doubt that they are PT. I'm glad you found it helpful, that is what I was hoping for.

Incorrect my friend. My tract home has NO pre or post tensioning. My driveway is the only slab that is post tensioned and there are only two arched cables for the entire slab.

jeffme 08-19-2013 2:11 PM

it is also important to note that you must READ and stamped noticed of PT concrete. In some cases it ONLY refers to the garage slab and not the house slab. You may be able to get information from the builder (based on age of structure). Check with your local building authority (city. county, etc) as they issued permits to the builder. As far as inspections of the concrete are concerned.......I have NEVER seen any inspector at each tract home inspecting concrete forms, placement, or finish work, including PT.

79camaro 08-21-2013 6:12 AM

Hi everyone,

I am new to the forum, but I just wanted to share my research on this subject. I also just purchased a new safe, and was wrestling with the issue of bolting it to a PTS. I contacted a VERY well known concrete fastener company, and purchased some 3 1/2" wedge anchors, I contacted them for guidance, and this is what they told me:

"If you have any doubt do not do it. Most post tension applications maximum embedment is ¾”. In fact now that I know your application, I will not sell you any other anchor. If you want return the anchors you have and I will give you a full refund on the anchors"

I thought that was rather severe, to refuse to sell me anchors (I guess we are in the era of big government/brother "watching out" for you!). But it made me think and research.

I found that Red Head makes the RX38 (3/8") drop in anchors that only need a hole 3/4" deep, and are specifically designed for a PTS.

I ordered some, and I think I will go with using the RX38s to anchor my safe. I know that ANY drilling is a risk, and I have to weigh out the risk of hitting a tendon. However, from several reliable sources I have determined that even IF I hit one, there is minimal chance I can sever or cut a tendon with a concrete carbide drill bit, using a hand held hammer drill. If I was using a rotary hammer drill, or actually cutting sections out of the slab...that would be another story.

I am not trying to argue with anyone, just sharing a possible alternative.

esp1 08-21-2013 6:31 AM

I was in a safe shop yesterday and the owner of the shop told me that you can just drill and that the cable is so tough that the drill will just go to one side of it since the drill won't be able to get through. And if this happens, just move the safe a little bit to move where the hole will be over and keep on drilling.

Then he quoted me $1300 for a 14 gun Amsec fire gunsafe.

79camaro 08-21-2013 6:33 AM

Pretty much that's what I've been told. I feel comfortable drilling 3/4"; HOWEVER, I have not dismissed the sticky idea of building the raised slab....My safe is one of those "inferior" $700 Winchesters, but it's MUCH BETTER than the Homak cabinet I was using before.

79camaro 08-21-2013 6:46 AM

SCOBUN,

Regarding the straps in step #9 of your sticky, where did you get them and do you have pictures of how exactly they go on the safe?

79camaro 08-22-2013 4:37 AM

Well, I am having more problems figuring out how/if I should bolt down the safe than when I was trying to decide WHICH safe to get! LOL!

I'm not sure I will build a raised slab in my closet, that might work great in the garage....but not in a closet. At the same time, I am having great doubts about drilling (even 3/4") into the slab....so I am leaning towards the 4x4s epoxied onto the floor and using lag bolts to secure the safe to the 4x4s

I plan on getting a security system, so I just want to slow down the burglar. Odds are that IF my house is broken into, it will NOT be a pro, but rather a meth head that is just looking for quick "grab and run" items. So, I don't believe he would even mess with the safe, and if he did, he would do minimal damage to it and the police get there while he's trying to figure out which kitchen knife to use on the safe!

John Browning 09-14-2013 11:37 PM

Quote:

Originally Posted by jeffme (Post 12105801)
Incorrect my friend. My tract home has NO pre or post tensioning. My driveway is the only slab that is post tensioned and there are only two arched cables for the entire slab.

It makes no sense to PT a driveway, but anything is possible. Unless your driveway is about 6 feet long it is also way out of code.

Quote:

Originally Posted by jeffme (Post 12105883)
it is also important to note that you must READ and stamped noticed of PT concrete. In some cases it ONLY refers to the garage slab and not the house slab. You may be able to get information from the builder (based on age of structure). Check with your local building authority (city. county, etc) as they issued permits to the builder. As far as inspections of the concrete are concerned.......I have NEVER seen any inspector at each tract home inspecting concrete forms, placement, or finish work, including PT.

Ok, now I know you're a troll. Inspectors are all over foundation work, and for PT jobs are usually on site. This is California. Everything gets inspected 10000 times more than is needed. Garage slabs and house slabs should also be one in the same if they are attached, or else you'd have major problems as they settle separately. I'm not surprised you don't know this. What state are you licensed as a contractor in?

Quote:

Originally Posted by esp1 (Post 12119841)
I was in a safe shop yesterday and the owner of the shop told me that you can just drill and that the cable is so tough that the drill will just go to one side of it since the drill won't be able to get through. And if this happens, just move the safe a little bit to move where the hole will be over and keep on drilling.

Then he quoted me $1300 for a 14 gun Amsec fire gunsafe.

These cables are coated in a red plastic. If you started seeing red plastic, you might be able to stop before you cause serious damage. However, remember that the cables are under huge amounts of tension. If you have ever tried to cut rope or cable that is under tension, you know how quickly it wants to fly apart. The owner of the safe shop has a whole lot less to lose by giving bad advice than you do in following it.

John Browning 09-14-2013 11:42 PM

Quote:

Originally Posted by 79camaro (Post 12119925)
SCOBUN,

Regarding the straps in step #9 of your sticky, where did you get them and do you have pictures of how exactly they go on the safe?

They came as part of the pallet of one of the safes I bought. On your cheaper safes there will be very little on the bottom and you can just use them basically as one big strap between anchor holes. It acts somewhat like one big washer and is great because the bottom of most gun safes would rip out long before the bolts give.

Quote:

Originally Posted by 79camaro (Post 12128773)
Well, I am having more problems figuring out how/if I should bolt down the safe than when I was trying to decide WHICH safe to get! LOL!

I'm not sure I will build a raised slab in my closet, that might work great in the garage....but not in a closet. At the same time, I am having great doubts about drilling (even 3/4") into the slab....so I am leaning towards the 4x4s epoxied onto the floor and using lag bolts to secure the safe to the 4x4s

I plan on getting a security system, so I just want to slow down the burglar. Odds are that IF my house is broken into, it will NOT be a pro, but rather a meth head that is just looking for quick "grab and run" items. So, I don't believe he would even mess with the safe, and if he did, he would do minimal damage to it and the police get there while he's trying to figure out which kitchen knife to use on the safe!

If I were putting a safe in a closet, I'd lag it to floor joists if they are there. If it is concrete, I'd probably build a false wall and try to conceal it. I definitely wouldn't put a raised slab in a closet.

Beauhooligan 09-26-2013 9:04 PM

Quote:

Originally Posted by scobun (Post 12317402)
If I were putting a safe in a closet, I'd lag it to floor joists if they are there. If it is concrete, I'd probably build a false wall and try to conceal it. I definitely wouldn't put a raised slab in a closet.

I have no knowledge about construction and just drilled and put anchors for 3/8ths high grade bolts to secure my three safes to the slab foundation of this house I own, built in '75. Now I am moving into my parents old house, built in the '50s, with a wooden joist foundation. This is a great house in one of the best neighborhoods in town. I don't even know about how the flooring and foundation will stand up to the weight of my big Champion safe, or even the two smaller Browning boxes. I'm thinking of hiring a construction engineer to take a look at the house and the details of the safes; weight loaded and footprint; and give me advice. I like putting safes in closets as it makes the safe harder to attack, and more costly to the crooks in terms of noise and time; seven years as a working cop gives me that perspective. Crooks don't like to make a great amount of noise, which increases the chance of detection, and time spent on the job is a matter of life and death. I'll bolt the safes to both floor joists and wall studs. That, combined with a really good alarm system, solid steel bars on the windows and gates on the doors, and a smiling black Chow, just might do the trick. But, I'm going to spend the money on the service of a construction engineer before I do anything, not even buy materials.;)

baaadmoon 11-21-2013 7:48 AM

PT Slab Safe install
 
Excellent info. Thanks so much ;)

beavis11 12-25-2013 9:44 AM

Another option for a post tension slab
 
Redhead RX-38 drop-in anchors. Only need to drill 3/4" deep. You have a better chance of winning the lottery while getting struck by lighting then you do of hitting and severing a PT cable drilling a 1/2" diameter hole 3/4" deep with a masonry bit.

1,571lbs-1,987lbs of tension strength per anchor. Shear strength of 2,295lbs-2,903lbs per anchor.

AdiosKali 03-01-2014 3:34 PM

Great info! I need to find out if the slab in my new house is PT. Never would have thought anything about it and drilled away:facepalm:

CWL 03-27-2014 10:55 PM

Great post and very timely! My house has PT slab flooring and I've been trying to figure out a cheap but effective way securing my safe in the garage.

Never thought it'd be that easy to add a pad on top of the slab!

Thanks!

SJgunguy24 03-28-2014 3:37 PM

Quote:

Originally Posted by 79camaro (Post 12128773)
Well, I am having more problems figuring out how/if I should bolt down the safe than when I was trying to decide WHICH safe to get! LOL!

I'm not sure I will build a raised slab in my closet, that might work great in the garage....but not in a closet. At the same time, I am having great doubts about drilling (even 3/4") into the slab....so I am leaning towards the 4x4s epoxied onto the floor and using lag bolts to secure the safe to the 4x4s

I plan on getting a security system, so I just want to slow down the burglar. Odds are that IF my house is broken into, it will NOT be a pro, but rather a meth head that is just looking for quick "grab and run" items. So, I don't believe he would even mess with the safe, and if he did, he would do minimal damage to it and the police get there while he's trying to figure out which kitchen knife to use on the safe!

I wouldn't epoxy 4X4s to the floor. Go with the drop in anchors into the pt slab. Just make sure you only go in 3/4" and you have the proper set tool that leaves the imprint on the face of the drop in anchor when it's set properly.
I've drilled thousands of drop in anchors, and suspended hundreds of pieces of HVAC equipment from those anchors. The key is you cannot drill two unless they are at least 10 times the diameter of the anchor apart.from each other.

John Browning 04-18-2014 8:54 PM

Quote:

Originally Posted by SJgunguy24 (Post 13751836)
I wouldn't epoxy 4X4s to the floor. Go with the drop in anchors into the pt slab. Just make sure you only go in 3/4" and you have the proper set tool that leaves the imprint on the face of the drop in anchor when it's set properly.
I've drilled thousands of drop in anchors, and suspended hundreds of pieces of HVAC equipment from those anchors. The key is you cannot drill two unless they are at least 10 times the diameter of the anchor apart.from each other.

One other thing to check is how drilling a PT slab impacts your home-owners insurance.


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