Having said that, what seems like a minor issue isn't. The T&G is a structural component of the subfloor and proper installation of a subfloor is to glue and screw or nail to the joists. A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. Also, donâ … Yes posters above are right. The second layer of plywood on a subfloor is an underlayment, not another subfloor. "I have learned so much thanks to the searchable articles on the FHB website. No glue, rosin paper between and over the field, no joist needed. • Place a layer of 15-lb felt on top of the subflooring prior to installing second layer. Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine. But if you are doing tile, different story. Every one of these answers are right in different situations and it depends on what want to be accomplished. Glue is not necessary on the second layer, but it won't hurt. Use these tips to keep cables tight and straight for a professional-looking deck-railing job. How do I install? I thought - to prevent squeeks - you were supposed to attach the 2nd layer to the subfloor below, not the floor joists. layer OSB or plywood floor interior dry or wet areas Limitations minimum 2" x 2" (50 mm x 50 mm) tile Requirements maximum spacing of joists, I-joists, or floor trusses is 24" (610 mm) o.c. The second layer must have a slip factor built in. 3/4 Inch Plywood Subfloor Preparation: Joist Installation. T & G or just plain square edge plywood? I’m thinking of adding a layer of  1/2′ or 5/8″ OSB on top of the 3/4″ T&G after the roof is on, which should be mid-next week. Why do you need to add the second layer of sub floor? Are you referring to the newer version of the IRC re. The subfloor usually runs in a continuous sheet under all the walls. Screw or nail the new layer down both into the joists and into the existing plywood using ring shank nails or deck screws. When I ask friends their opinion on my flooring layers needed for tiling, I usually get one of the following (conflicting) answers: 1. When you are installing tile on a second floor, you may be concerned that the floor isn't strong enough to support the weight of tiles and mortar. Parallel or perpendicular … The second floor of this house is built with 2 x 10 wood I-joists (joists that resemble steel I-beams and are 9.5 inches thick), 16″ on center and spanning 13.5 feet. Just be sure to stagger the seams. If you're dead set on the extra layer though, I think you're going to need to put a slip layer of building paper between the two layers of flooring before screwing through to the joists, or orient the one layer perpendicular to the other, apply plenty of high-strength waterproof glue and then screw the whole thing … Lay the first row by starting with a full panel, then cut the last panel to fit if necessary. Feet will sweep up and over with little chance of trippage because there won't be a sharp or severe lippage. Make sure first layer is screwed tight to the joists. This is new construction. With the first layer of the floating subfloor down, the guys pile more sheets that will become the second flayer of subflooring. Get a floor sander and hit those expanded edges to even it out and be done. The first layer was laid the long way, across the main part of the house into the … Attach the smaller piece to the subfloor with a 1-inch wood screw every six inches in each direction using a power drill. All good. plywood double layer wood floor consisting of: • minimum subfloor thickness – 23/32", 3/4" nom. 3. Lay down a layer of 1-inch Styrofoam insulation, cutting around the wheel wells and covering the entire floor space. If nailed, re-screw. Stagger the joints as suggested and use plenty of construction adhesive and screws. https://www.fema.gov/media-library-data/20130726-1708-25045-9326/chapter7.pdf, VerticalScope Inc., 111 Peter, Suite 901, Toronto, Ontario, M5V 2H1, Canada. another layer of plywood, glued and screwed on a six inch grid. Then there's no complications with stairs and entries. Can't hurt to do both in my opinion. No glue, screw second into first layer (not joists) and stagger the seams. To illustrate. It can’t be removed easily. Thanks for any advice. Install a cement-based backer board following the manufacturer’s instructions. Typically made of plywood or OSB and ranging in thickness from 19/32" to 1 1/8" thick, the subfloor is truly structural, second only to joists in this respect. 3/4″ T&G was rained on several times. Watch remodeler Josh Oduin demonstrate how to embed premade corners and banding in thinset to waterproof a new shower before tiling. Here I was thinking it meant you poured cream along the joints and let the cat in. When the whole project is completed, there will be a finished floor installed on top of the rough subfloor. When screwing down a second layer of subfloor on top of the bottom layer, should I. Your subfloor provides an excellent, level foundation for the flooring of your home. However, a double layer of 3/4" osb glued and screwed is super stiff - ideal really. Question I have is “If I add a second layer of OSB should it run the same direction as the first layer and overlap the seams or should it run perpendicular to the first layer?”  Glue and nai lto the joists as the first layer or maybe screw it thru the first layer? I'd lap all the joints in both directions and screw it down to the joists. I think I can adjust the stairs. Edge Gold includes patented Down Pore ® grooves that help shed standing water and a proprietary edge seal to reduce … Thanks. However, many subfloors might not be the ideal surface on which to lay your finished floors. If existing subfloor is 3/4 " t@g boards- screw 2 or 3 1-3/4 screws into every plank , every joist prior installing 3/4" t@g real plywood. Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features. You can install carpeting and wood flooring directly over the plywood. also-that'd only be less than a 2 x 2'-6" sash. 3/4″ T&G is glued and nailed. Follow up with a layer of 1⁄2-inch oriented strand panels — which will make up the subfloor. If this is the only option then place the second layer of plywood in the opposite direction of the existing subfloor and use construction adhesive between the layers, NOT thinset. For example, just did an addition with 5/8" ADVANTECH, 1y" OC joists, and then since it was going to be carpet your basic carpet base.....put in with about a million staples. © 2020 The Taunton Press, Inc. All rights reserved. (19 mm) tongue-and-groove • minimum … But 32"? Do not line up joints - overlap them about 4 … Some flaking. Any suggestions? glass? This video covers measuring , cutting , and the correct tricks for installing, to ensure a good bond and long lasting results that never squeak! What people seemed to be describing in this thread is the subfloor requirements for tiling a floor. While removing the old subfloor, mark the locations of the nails on the walls to help you install the new sheets. For the second row, cut the first subfloor panel in half. If yours isn't, then now would be a good time to make it so. I'd question the 4.5 s.f. Install Plywood Sub-Flooring Before you lay new wood flooring, vinyl tile, carpet or other floor materials, you'll want a smooth, even sub-flooring installed over the old floor.