How To Fasten Anything To Concrete

Attaching Luan to Concrete Floors, is possible if you first overlay the concrete with a think material such as plywood, then use the Laun Material overtop of that. Many thanks to Martin and others that impart knowledge,it is much appreciated.I thought you might be able to affirm or redirect my plan to better heat a three story open space that is very cold on the first floor due to heat rising.I plan to lay 1 inch of XPS on unisulated concrete slab,apply 3/4 strapping,adding 1/2 inch pex with s and covered with 3/4 plywood and laminate flooring,yes headroom is an issue,but am willing to sacrifice some to not compromise it.

I’m an amateur, but it seems logical to me that if a little moisture seeps in at all through the slab (and I know this will happen a bit, as I see a little now before I’ve even started, even thought I sealed it with concrete sealing paint), that the vapor barrier will keep everything dry, except where the infrequent nails holding down the concrete are located.

I wouldn’t even paint it, but if you want to, go for it. If you cut a 1.5 inch strip of plywood off of one of the sides (consider that you may want to keep the 4 or 8 foot dimension to line up with studs before cutting), then cut the strip into 2 inch segments you can attach those to your wall studs spacing them out in a grid (16 by 16 inch is good).

I would not count on long term success with regular steel fasteners holding PT wood on to a concrete floor. The terms house bolting, foundation bolting and cripple wall bracing are often used synonymously with earthquake retrofitting. The National Wood Flooring Association recommends two choices in sub-flooring systems for concrete installations: plywood-on-slab and sleeper. Even if a concrete slab appears to be dry, groundwater can seep up through it and damage the flooring from underneath. Lag Expansion Shields are designed for concrete and the mortar joints of block and brick.

The quickest, easiest way to drill into concrete is with a hammer drill, which uses both bit rotation and concussive blows to bore holes. Prepare the slab floor as discussed in Preparing Plywood-on-Slab for Hardwood” (above), but instead of rolling out polyethylene sheeting on the concrete slab, embed the 2-by-4 sleepers in thick lines of asphalt mastic. Note: Remember to stagger the plywood; it will make for a much stronger floor overall. Instead use a commercially available sink support system or build one of your own using plywood or 2x4s.

Well, we used those narrower planks up against the wall and were able to custom slice them down even narrower if the wall happened to have a slight bow to it or whatever. I’ve spoken to a couple hardwood floor installers and that is what they would do. I am in California so climate conditions are quite moderate. Using the new figure, measure along the parallel centerline to each end of the starting wall and make a mark. The Florida Building Code recommends a minimum thickness of seven-sixteenths of an inch for exterior-grade plywood. Once you’re satisfied that everything fits together as it should you can start attaching.

Of course it should go with out saying that a concrete subfloor that has a basement under it or is on the upper level of a modern building will only experience moisture problems at the edges of the floor. Though do-it-yourselfers can install wood flooring on a concrete slab, this job is not for the novice. Professional installers use a moisture meter and other methods to test the body and the surface of the slab for excessive moisture. You could also use a sheet good other than plywood that is already moisture-proof.

Generally, the need for holdowns is a function of the height-to-width dimensions of a shear wall configuration. Reasons include better stability which translates into fewer problems and no need for a plywood nailing base. Try 1/8in masonry bit and a hammer drill 2in fluted masonry nails and heavy duty construction adhesive, make sure your concrete is clean and dust free. I don’t see anything other than concrete or lbocks or stones , getting through a flood or a very bad leak. The moisture level of the concrete should be down to 5.5% before attaching the plywood subflooring.


All lumber and plywood shall be pressure-preservative treated and dried after treatment in accordance with AWPA U1 (Commodity Specification A, Use Category 4B and Section 5.2), and shall bear the label of an accredited agency. I glued 1 inch thick rigid foam board onto the concrete floor which I had previously treated with a 1/16 inch coating of xyprex moisture proofing. A custom connection upgrade is to use Angle Iron Struts, which connect the floor joists directly to the foundation in a similar fashion to the Simpson FJA anchors.

Even for a slab on grade here, u still need to install footings at ~5ft depth, so again either bocks or concrete is required there.posts are probably much more expensive. However, due to the cost of the adhesives, it can be slightly cheaper to use the plywood method. Holdowns are specially constructed right-angle brackets connecting from the cripple wall framing into the foundation.

These fasteners are commonly used to attach medium duty curtain walls to structural steel or concrete at the perimeter of a building. If the concrete has any areas which are uneven, they need to be corrected before the plywood subfloor is installed. Designed for concrete anchoring, they require a pre-drilled hole the same diameter as the anchor. With concrete slabs potentially weighting hundreds of pounds you don’t want to have to load and unload looking for the next piece.

Soft story conditions can sometimes be improved by installing plywood bracing on a wall that is next to and inline with the opening. To assist the glue you can use powder actuated nails, Tapcon screws, or expanding concrete anchored screws. The wait is so that all of the moisture in the slab, and it can literally be tons of water, can evaporate before the wood floor goes down.

Today there are mastic type moisture compounds that many professionals use if initial concrete testing shows unacceptable concrete conditions. The biggest drawback for the T&G was knowing the shop will go through many changes over the years and if I used T&G I would lose the option of pulling up sections of plywood to run wiring under the floor. Then when the rest of the planks were down, we’d come back and lay in the planks that butt up against the wall. I ran this through my head while looking at the floor and there seemed to be a better way.

Using the same methods, place sleepers across the slab on 16-inch centers, perpendicular to the direction the finish flooring will run. However, a good understanding of shear wall mechanics is helpful in deciding whether to save the cost and work of holdown installation. Use a powder-actuated fastener tool with powder-actuated fasteners (are used with concrete and steel) to secure the plywood to the concrete. Dip the trowel into the adhesive and spread the adhesive out over the entire surface of the plywood with the trowel.

Layout the cement backer board at right angles to the plywood subfloor so the joints in the backer board are staggered and don’t fall on joints in the plywood. Yes, it is always best practice to stagger the boards, there is a good reason for it, it keeps any continual lengths of gaps away from any floor board edges. For lightweight anchoring in concrete, hollow block and brick, solid brick and wallboard applications. The hole in the plywood must be large enough to allow for the sink to be moved to align it with the hole in the countertop. The struts reinforce any weakness in the original sill bolts and extend the anchor more completely into the house’s main floor platform.

Use them in one or more of the following materials as indicated: drywall, gypsum wallboard, plaster walls, hollow doors, thin panels, wood paneling, hollow brick and hollow block. The floor is basically trapped in it’s own glue, and the stress of even minor expansion just wrecks this type of floor installation. Most professional installers use two methods for attaching the subfloor to the concrete.

Learn how to properly install AdvanTech subflooring to deliver the quiet, stiff floor homeowners want. Concrete slabs, whether new or existing, must be dry before the subfloor is installed. They also perform better when the earthquake force is expected to cause an uplift — a situation where the movement pulls the bolt upward and out of the concrete. I’ve seen hardwood installs over concrete using a floating plywood subfloor (with a plastic waffle shaped layer attached on the bottom of the plywood) to hold the flooring up off the concrete.

The glue was applied heavily over the entire floor to act as both a moisture barrier and an adhesive. The following analysis provides a general idea of what to expect when adding a plywood sub floor to concrete in preparation of installing a traditional ¾ inch nailed or stapled floor. That’s why experienced builders pay close attention to minimizing expansion and contraction when preparing to install this traditional material, especially in concrete slab construction. The split drive anchor is a one piece, fast and easy-to-install concrete anchor that comes in a flat counter sunk head. I pre painted the underside of the plywood with a sealer/primer type of product.