Hi all. I’m adding some stairs to a deck. I have a small landing in the midst of the run (approx 3 X 5 foot). the 5 foot length of the landing is right up against the poured concrete foundation (about 4 feet above ground). the landing will have a ledger attached along its 5 foot length and the other 2 corners supported by posts on poured footings.
What is the best way to attach the ledger to the concrete foundation wall? (poured reinforced concrete foundation about 8 or 10 inches thick, not block).
if i rent a heavy hammer drill and drill 3 or 4 say, 1/2 inch holes and then use threaded rod or long bolts to firmly attach the ledger board to wall, that seems very secure? does a hammer drill weaken a concrete structure other than the hole it drills?
or would a bunch of tap-con screws be better? it would be smaller holes not going all the way through the foundation, but i’m not sure about relying on tapcons (in shear) for the load (over time). i’m assuming they would begin rusting?
any thoughts would be appreciated…
thanks, David S
PS. the house i’m doing this on is in N. Carolina on the slope of a mountain, so the integrity of the foundation is paramount!
Replies
We mostly use Stainless wedge Bolts for things like this. You probably don't need stainless. The Wedge Bolt is like a big Tapcon, quick, easy and holds well.
http://www.powers.com/product_07246.html
I'd say use a "belt and suspenders".
Use some structural epoxy in the hole before inserting the Red Head (or fastener of your choice). Simpson sells this in self-mixing dispensers that fit in a caulk gun. They work really well.
Whatever method you use, be sure to clean out ALL the dust and debris before putting in the fastener.
Don't need any of that stuff with Wedge Bolts.
thanks guys for the info.
Florida, the wedge bolts look good. i'll check with a supplier nearby. the spec sheet says you have to use a special ANSI rotary drill bit. i'm assuming the bolt supplier sells those too?
thanks again....David S.
Look into Simpson's Titen screws - 1/2 hole to 1/2 screw - they cut their own threads in the concrete - need an impact wrench to tighten them.
I would problaby use these http://www.grkfasteners.com/en/CLB_0_XL_information.htm
They work great.
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Concrete Flat Washer Head Screw
Caliburn™ screws are professionally engineered fasteners for concrete and similar applications. They feature a patented thread design for ease of driving the screw. They are available in different head designs for multiple applications with the recommended GRK™ Drill Bits. Caliburn™, Caliburn™ PH and Caliburn™ XL are Climatek™ coated for high corrosion resistance.
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Rent a Bosch Bulldog and a ½" SDS bit. Drill 1.25"-deep holes on 16" centers where you want to mount the ledger. Put long 5/16" lead lag anchors into the holes, then mount your ledger using 5/16"x2.5" lag screws and washers. Pre-drill the ledger so the lag screws won't 'bridge' and hold it off the foundation wall.
Lead lag shields (anchors) are quite a bit less expensive than Hiltis or Red Head wedge anchors and work as well or better in these sizes. You usually don't need the heavy artillery until you get to 5/8 or bigger, and you don't need anything that big to hold up that deck or stair landing. 5/16 will be fine.
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How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
Yes, you can gets bits where ever you buy the bolts.
thanks folk. never realized there were so many products/systems to attach to concrete. i was able to find a supplier for the wedge bolts and bought some plus the special bit.
I think that will do nicely. Also folks, thanks for the idea about using some sort of a spacer or stand-off to hold the ledger just a bit away from the wall. that's a good idea and will help to keep moisture from staying between the ledger and the concrete....
cheers, David S.