I figure the wind pressure exerts a force on the side of the shelter and then to the anchors through some distance of steel wall. The wall of the shelter then acts as a lever, now having additional torque. I was wondering how to do a back of the envelope calculation for this to figure out if the...
Thank you. I paid a guy $400 to come out and locate my post-tension cables and rebar with his ground radar. He kind of said off the cuff it looks like you have 5"-7" of concrete. I wish I had pressed him now to be more specific.
Does any one know how to do the calculation for the force the...
It did seem sketchy to me too. After talking to several of these shelter companies, they are all doing something weird with the anchors (including the most notable ones). The owner claimed they did't make the short version when he started.
Ground radar showed I have approximately 6" of...
I just knew that epoxy anchor strength was superior to screw anchors according to Hilti datasheets, so I wanted to add epoxy. The other concern I had was that they are using the 7" HUS-EZ which are not intended for exterior applications, yet they will be completely penetrating the slab and into...
I'm having a steal storm shelter anchored to my garage floor with the 3/4" Hilti HUS-EZ screw anchors.
Does any one know if there is a concern about adding epoxy to the holes before we screw them in?
I dont have any other anchor options because that is what the engineering drawings require. I...
Dick,
Builders/Installers are required by the NSSA and ATSA (storm shleter assiciations) to follow FEMA guidelines and pass a debris impact test at Texas Tech. Interestingly when you look at these documents, there aren't any rules for strictly steel shleters. FEMA 320 specs wooden and concrete...
Yall, made a good point about having it measured/checked. Noted! One website said PT slabs are usually 8" (heck if I know). If that is true than I could use just about any anchor and be in good shape. FEMA requires a 4" minimum slab, so I shouldn't blow away! I just didnt want the anchors to be...
I live in Texas, we have major foundation issues here because of the clay soil. One local shelter company told me they won't do INGROUND shelters on newer homes in the garage because they dont want to cut the PT cables. Hmm. Wonder how I can get this slab thickness measured?
My house was built in 1999, so I've been told everying after '95 or so has them. I see steel poking out of the side of the house every few feet, I assumes that was the post tension calbes?
I found this table on steel corrsion rates. When the anchor is in the dirt it would corrode faster. Any thoughts?
At this point, I think I'm more likely ot die trying to solve this than I am to get hit by a tornado!
The (uniform) corrosion rate of steel in different atmospheres:
Atmosphere...
Thanks guys,
Considering that the concrete depth could vary a lot & I might not have enough concrete below the anchor to meet Hilit's specs, what would be the best choice: Epoxy, wedge, or screw anchors (HIT-Z, Kwick Bolt3, HUS-EZ) As I already stated, I'm concerned the zinc HUS-EX will rust. I...
Thank you. I noticed the 3/8" anchor, but since FEMA 320 requires a 1/2", I dont think any shelter company would use a 3/8" anchor. Part of the problem seems to be that no anchor can meet the criteria. (>=1/2" diameter, ~3" embedment, 4" slab, pull out strength ~1800 lbs, made in the USA)
The...
