Underlayment and Subfloor Screws provide strong and long-lasting holds for securing both underlayment and subfloor in subfloor installations. What size number and length of screws should I use to screw 1/2 plywood underlayment to subfloor? • Apply a supporting bed of dry-set mortar or modified thinset to plywood with a 1/4 in square-notched trowel. I've heard that before but some others told me that size is too large. View Full Version : screw pattern for underlayment / tile on plywood. VerticalScope Inc., 111 Peter, Suite 901, Toronto, Ontario, M5V 2H1, Canada. I can't use t&g because I had to cut out a weird shaped section that was all rotted. (This material will work well as underlayment, unless you have a particularly weak or “spongy” floor, or if you intend to install ceramic floor tile, which needs a stronger base – see next page.) JavaScript is disabled. It really helps. You screw down the subfloor to the joists, as you stated, and then attach the underlayment to the subfloor (but not to the joists). I'm not sure what the relevant units are either. Instead, fasten the plywood underlayment panels with staples, ring-shank nails or screws. I screwed it into the base of the walls frames and the plywood lips, and glued the crap out of it. In my case, I'll use 1-1/4" length fasteners. Floorboards vary in width and thickness but you may be lucky and they may be 18mm thick. 1" TABLE 2 SHEET METAL SCREWS: PLYWOOD-TO-METAL CONNECTIONS(a) Plywood Ultimate Lateral Load (lbf)(b) Thickness Screw Size 1/4"-20 Self Plywood: All values are for 16 gauge galvanized wire staples having a minimum crown width of 3/8". Underlayment’s special face and inner-ply construction resists dents and punctures from concentrated loads. Ok, so, please dont crucify me but this is what I ended up doing. All you you are attempting to do is add more rigidity to the subfloor and supply a superior nailing base. Try to create a random pattern with the nails so they will not appear in a regular pattern through the flooring. Normal application with just 3/4" I would squirt down some construction adhesive to the joists, lay the 3/4" layer and screw 8" on edges and 12" in the middle. Patriot Timber Products, Inc. 117 S Westgate Drive Greensboro, NC 27407 Fax: 336-299-4050 That's why screws are used...not staples...not nails. I put a 2x8 under the left and right sides to make a nailing edge. Originally, I asked my builder about the suggestios I got from my other post to put 1/4" plywood underlayment down then put a concrete board down (wonderboard something like this). Fasteners every 6-8 inches in all directions. The squeaking comes when the plywood dries (it shrinks back away from the holes) and the nails/staples begin to RUB against the plywood that is moving. Then, nail 1/4” mahogany plywood right on top of your Underlayment nail existing floor. Vapor barrier is recommended. It can also be used under hardwood, laminate, and carpet, but this is much less common these days because subflooring is typically smooth enough for these materials, many of which are installed with a different type of underlayment or pad. • Use the fastener pattern as a guide. Screw or nail the new layer down both into the joists and into the existing plywood using ... and set 1/2" cement backer board in it staggering the joints from the plywood and between rows. (b) Values in parentheses are estimates based on other tests. In this case you have a choice of chipboard, mdf, I guess OSB or floorboard timber. If this is a concern, marine-grade and underlayment-grade plywoods will avoid the voids. How should I screw it down? Avoid using materials with distinct raised grain patterns, which can affect the finish texture of the sheet vinyl. When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions. Then I consulted the FAQ from www.tecspecialy.com and they said you must use the latex modified but as long as your substrate is over 1 1/8". So 32" is the smallest it should be, otherwise you add an underlayment over the sub. This is fine if you're not worried about the long-term durability of your work. I'm using ungrooved 3/4 inch treated plywood and no glue, if that makes a difference. In my particular case, I'm building a tiny shed. ). TILE GUY - retired- TROY, MI - Method & Product suitability consulting. So I just ignored them and went with Ditra (which by the way I was told by one flooring store, I only needed for floors that had poor deflection) I would rather do something once than over again. Never use adhesive on the sub-floor to attach the plywood underlayment. Plywood underlayment is a thin plywood material that is most commonly used under resilient flooring materials, such as vinyl and linoleum sheets and tiles. Always protect plywood underlayment from moisture or damage prior to installation. Gotta Make it difficult, don't want to follow the rules. Yes, I thats the plan. If the plywood subfloor you’re placing is 5/8 of an inch thick, you need a screw about 1 5/8 inches long. Faster, easier, and far cheaper to use 8D ring shanked nails. Side plate was 3/16"-thick steel. I bought subfloor glue and will be putting it on the joists (should I just do a zigzag?) A final mark to check is the thickness of the plywood. Plywood sheets are laid perpendicular to the subfloor, with no common joints and no adhesives between the layers. Attaching plywood and OSB sheathing by Mark S. Graham Slightly different fastening schedules are provided for three wind-speed regions— 90 mph, 120 mph and 150 mph—based on the basic wind-speed map contained in ASCE 7-02. I'm getting a new home built and wanted to do the tile which the builder agreed to let me. Many people don't bother to glue down their plywood underlayment. Some of us are easily confused. I am thinking #8 length 1-1/4 inch, but I am really not sure. Once the point has pulled a wood screw down into the material, it’s up to the threads to continue driving it the rest of the way in. The proper screw sizes for securing 3/4-inch plywood to the floor joists are the same as steel screws. Underlayment is a special grade of APA plywood that is attached on top of the subfloor to provide a durable and resistant layer under finish flooring. 1: Handling Underlayment. Easy and inexpensive to replace, cut to width and screw down. Unlike nails, the MTH underlayment screw has an intricate high-low thread pattern designed to prevent squeaking by holding underlayment tight to the subfloor and thus preventing withdrawal. Fasten HardieBacker cement board with specified nails or screws (as listed in “Materials Required") every 8 in over the entire surface. molding”). Jaz . Todd I've merged your threads so we can better answer your questions & keep track of you. Screws are preferred over nails for subfloor and underlayment installations as they provide strong and tight connections that help prevent the floor from squeaking. Choosing the Proper Fasteners for Installing Plywood Underlayment. So if your subfloor is 3/4 of an inch thick, any screw about 1 3/4 inches long will do the trick. A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. Mahogany plywood is smooth on both sides. Wear safety glasses when nailing the plywood to protect your eyes from any debris. Ceramic Tile Advice Forums - John Bridge Ceramic Tile, screw pattern for underlayment / tile on plywood. Plywood underlayment panels should be laid in an offset pattern as shown in the Flooring Diagram so that four corners never directly intersect. felt or Feltex) Plywood Thickness (in.) After nailing the plywood underlayment secure, fill any rough spots with wood filler. I have 3/4 inch thick plywood screwed to joists already and I am going to add secondary 1/2'' plywood underlayment on top of it for more stiffness because I am going to tile marble floors. Please do yourself a favour and find the underlayment grade product that has the screw patterns tattooed onto the sheets. When installing 1/2" CDX plywood over an OSB or plywood subfloor, it is not necessary to staple, glue, and screw. :D. vBulletin® v3.7.4, Copyright ©2000-2020, Jelsoft Enterprises Ltd. The underlayment will be Ditra. Bottom Edge Screw Pattern – apply to every profile except for MD36 (1 screw beside every rib) High wind or Low pitch applications Stitch Sheets Butyl Tape All roof and wall sheeting requires ¾ to screw to either ¾ plywood or 1x4 standard spruce strapping. I do have an impact driver so that's nice. I checked my Tile Book from JLC publishing by Michael Byrne and Michelle Griffoul - page 173 says, "For extra strength and rigidity on stone-tile installation and where deflection may be an issue, I also prefer to glue and screw the plywood underlayment to the subfloor with type 1 or type 2 water-resistant carpenter's glue and corrosion-resistant screws." For best results under resilient flooring, sanded-face underlayment-rated plywood panels (or their equivalent) should be staggered at the joints, spaced 1/32 inch apart, and fastened according to the schedule above.Before installing floor covering, fill all seams and holes with quick-setting filler and sand smooth when fully cured. Mastic can also be used with a 5/32 in V-notched trowel. before I screw them in. Helping You to Do It Yourself! June 9th, 2014. TILE GUY - retired- TROY, MI - Method & Product suitability consulting. (a) Plywood was C-D grade with exterior glue (all plies Group 1), face grain parallel to load. I also called the place that I bought the tile and they said the same thing only to put thinset between the 3/4" OSB that I have and the 1/2" underlayment (which I didn't like in my mind I see not being able to expand issues with the plywood???). I'm going to put down some 1/2" Fir plywood over 3/4" OSB. Stapling down with 15 gauge 1&1/2" legged staples with 1/2" crowns alone is sufficient, as long as use use lots of staples. Jump to Latest Follow 1 - 10 of 10 Posts. Instead, they just screw or nail the boards to the subfloor. This class of plywood is appropriate for use outside as well in areas of the building that may experience contact with water, such as bathrooms and kitchens. For a better experience, please enable JavaScript in your browser before proceeding. Whoaa, 2 1/2"! Good Old Wisconsin. Hey there, I'm getting read to screw and glue some subfloor in. The subfloor is 3/4" plywood with 1/2" plywood on top of it. Most underlayment-approved plywood is at least 11/32 inches, the standard recommendation. My main question here is about how to secure to the joists. So it will be your house, do what is comfortable for you. Come join the discussion about tools, projects, builds, styles, scales, reviews, accessories, classifieds, and more! Conventional wisdom has always been that screws with fine threads are best for hardwoods — oak, cherry, maple, birch, etc. It would be best to screw the second layer only to the first layer delibertly missing all the previous seams and missing all the floor joists. Fastening SurePly ® Premium Plywood Underlayment ;) Actually I am in Madison and have gotten the same response from several builders and flooring shops. 4 to 8 inches along the edges, 8 to 10 inches in the field will do nicely. I had originally planned to use ring-shank nails, but can't seem to find 1-1/4" ring shank … Cut and place SurePly ® plywood underlayment on the subfloor without any fasteners, or "dry fit" all panels first before beginning any fastening. Plywood used as underlayment for sheet vinyl flooring should also have a sanded, smooth surface on the topside. I tried to educate one of them with my limited knowledge (I know just enough to be seriously dangerous) and directed them here, but to no avail. I would suggest that any damaged, split, short lengths of board are replaced with new timber. To screw them in, I was planning on getting #8 2" fully threaded construction screws. Underlayment to Wood or Steel Screw The MTH underlayment screw is designed for fast and secure underlayment to subfloor installations. The experts will explain tbe reasoning behind them. Originally, I asked my builder about the suggestios I got from my other post to put 1/4" plywood underlayment down then put a concrete board down (wonderboard something like this). Your floor is ready for a vinyl covering at this point. When choosing an underlayment, look for a product that has an APA stamp that specifically says "underlayment." Before installing, allow underlayment panels to acclimatize by standing them on edge and separating them to permit air circulation for several days in the rooms where they will be installed. You’ll want the screw to go about an inch past the plywood into the joist or underlying layer beneath it. He had a real problem with it and called his tile people and they said to use the plywood that they have had problems with the concrete backer board for flooring. (336) 299-7755. (15 lb. A seam overlap of a minimum of 25% is the way to go. Screw pattern and size for 3/4" plywood subfloor? — while coarse-threaded screws drive and hold better in softwoods, plywood and composite sheet goods (particleboard, MDF, etc. Screw Head Types Screw heads have indentations that allow a particular drill head to put torque on the screw, drilling it into the plywood.