How To Attach 4x4 To Concrete Deck Block
Determine how much stress the fastener needs to resist for the connection between the concrete block and the wood.
How to attach 4x4 to concrete deck block. Can i attach my deck to a hollow block concrete foundation. Also if you drop set the framing into the groove the underside of the joist is still 5 6 above grade. I d like to know if i can pour concrete piers and attach the 4x4 posts to the top of them slightly above ground level with metal anchors. Some landscape designs call for a deck to join with a cinder block wall at a property line a building or a planter.
I used them for a lean to on my house and they worked great. Precast blocks that are available at home improvement centers usually are 12 inches square and 8 to 12 inches high. A third option for attaching a post to solid concrete or concrete block is side mounting which works well on an elevated masonry base such as steps or a raised concrete porch. Cut pieces of pt 4x4 post to fit from the top of the double ledger support to the bottom of the deck ledger above.
Some are made with notches designed to hold standard size posts beams and joists. However most concrete deck blocks can only hold 4x4 posts not 6x6s and they have no lateral strength at the base of the post. Deck piers support the beams that create the joist spans for a deck. I ve used these for years with great success.
Unlike a concrete footing that distributes the weight of the structure over a large area piers concentrate the load to a small area. High decks into unfinished basements. Attaching wood to cmu concrete masonry unit is possible using several procedures. The deck to block connection is done.
A good rule of thumb when side mounting is to attach at least one third of the post below the top level of the concrete. Yes there are products available for anchoring a ledger board to hollow concrete block foundations concrete masonry unit cmu. Additionally determine if you must make the connection removable or permanent. Confirm with local building code to fasten a deck ledger to an exposed basement wall use the same through bolt procedure as described for brick veneer above.
See the image below. There are a handful of manufacturers that produce epoxy and other adhesive anchors that are tested for use in hollow cmu. A recent wind storm snapped 2 of my 4x4 cedar fence posts taking 3 panels with them. The area of my yard is low lying so it is often wet and i thought if i buried the posts they would.
Using that tiny l bracket to attach a deck post to concrete is like using a piece of thread to hold a cruise ship to a pier. So you may want to build a deck that is lower to the ground. How to hang a deck from cinder blocks.