On the 3/4" subfloor, you have the right idea. Use subfloor adhesive, and screw 8" at edges, 12" in field. For the 1/2" underlayment, ideally, you want to screw every 6" all across the panel. Adhesive will help you here, as the subfloor plywood will have voids in spots that will not hold a fastener..
Likewise, people ask, does subfloor need to be glued?
Glue. Although using a subfloor adhesive is not required by code, it is a standard practice that can help prevent floor squeaks by reducing the chance for movement at the panel-to-joist connection. A quality subfloor adhesive will also increase the overall stiffness of the floor.
Similarly, what screws should I use for plywood subfloor? Steel Screws The proper steel screw sizes for securing 3/4-inch plywood to the floor joists are #8, #10 and #12 screws. The number refers to the thickness of the screw. Each is available in lengths from 1 1/4 to 3 inches. Typically, the 3-inch variety is used to secure plywood subfloors.
Similarly, it is asked, how many layers of plywood do you need for a subfloor?
Personally, I would also make sure the floor joists are close enough together to give good support. Two plywood layers would span 24 inches in most cases, but if you want to get by with one layer, spacing the joists at 16 inch centers will give you a better floor.
How many screws come in a subfloor sheet?
Use 8d common nails, spaced 6" apart on edges and 12" apart in the field. 1 1/8"-1 1/4" panels. Use 10d common or 8d deformed nails, spaced 6" apart on edges and 12" apart in the field.
Related Question Answers
How thick should a subfloor be?
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. Subfloor holds up all of the above layers of flooring, as well as everything in your house—people, dogs, cats, pianos, furniture. All houses have subfloors.Should subfloor be screwed or nailed?
Overall, screws tend to be somewhat more expensive, but like nails, some offer better quality for a higher price. With that said, it's imperative you choose a fastener compatible with your subfloor thickness and material. The quality and correct type of subfloor fastener can literally make or break your floor.Can I put new subfloor over old subfloor?
One of the benefits of removing the old flooring is it allows you the chance to fix any loose subflooring or squeaks by re-securing the main subfloor to the floor joists prior to installing the new flooring. With all that being said though the answer is YES you can install New Wood Flooring over the old.How long does it take to replace subfloor?
Replacing a small portion of subfloor can be quick and easy for a professional, however replacing an entire floor will take much longer, anywhere from 8-24 hours. In order to replace the subfloor, the finished floor needs to be removed first. If there is an underlayment that will also be removed.What kind of plywood do you use for subfloor?
While OSB is the most popular structural panel, CDX plywood is the most popular type of traditional or "veneer" plywood. CDX plywood is like other laminate plywoods, but the outer layers of laminate are grades "C" and "D," which means they are cosmetically rough and contain many imperfections, thus lowering their cost.How do you install plywood subfloor in a bathroom?
- mark cut lines on plywood using T square. Mark the Cut Lines.
- cut plywood to size with circular saw. Cut the Plywood.
- mark floor joist locations on wall. Mark the Joist Locations.
- lay plywood in place on floor. Lay the Plywood.
- drive deck screws every 8 inches along chalk line. Insert the Deck Screws.
What is the best construction adhesive for subfloor?
PL400 sub-floor adhesive is the best choice for securing sub-flooring panels to joists. PL400 allows for easy gunning whether you are outdoors or in and can be used on wet, frozen or treated lumber and its elasticity helps eliminate squeaks.Can I use drywall screws for subfloor?
Drywall screws should only be used for drywall, and a temporary coat hanger. You want more strength and need less space for the threads to secure the subfloor. The drywall screws have a lot of thread to hold the drywall itself, but have very little shear strength. In the field between the joists, they are fine.How thick should a bathroom subfloor be?
Make Sure Your Subfloor is Structurally Stable The installation guide for 1/4 inch HardieBacker recommends having wood subfloors made of 5/8 inch exterior grade plywood or OSB (oriented strand board) that is 23/32 inches thick.What size plywood is used for flooring?
The thickness of your plywood subfloor depends on the joist spans. The National Wood Flooring Association recommends a minimum plywood panel thickness of 7/8-inch for joist spans of 19.2 to 24 inches, and a minimum plywood panel thickness of 5/8-inch for joist spans of 16 inches or less.Does subfloor have to be tongue and groove?
For subflooring, you use tongue and groove plywood. The tongue and groove are only along the 8 foot edges. On the four foot edges, your seams will fall on joist tops, so no need for tongue and groove.What can I use as a subfloor?
Plywood has been a standard subfloor material since the 1950s and remains the preferred subflooring for many builders. Standard plywood can be used for subfloors, but a better material is 3/4-inch tongue-and-groove plywood subflooring.Can you use treated plywood for subfloor?
Kiln-Dried-After-Treatment Agreed. Under the IRC this 19% or less moisture content lumber is called kiln-dried-after-treatment lumber and is perfectly acceptable to be used in structural sheathing, subflooring, or framing.Can I glue plywood to concrete?
Plywood can easily adhere to concrete. One way to attach plywood to a concrete surface is to screw it into place with concrete fasteners. Another way that involves less strain and hard work is to glue the plywood to the concrete. This only requires a few materials and will adhere the plywood very securely in place.How do you attach plywood subfloor to concrete slab?
To install a floated subfloor system, first place a layer of plywood subfloor panels with the edges parallel to the wall. Use a ¾” spacer between the plywood and the wall and a 1/8” spacer between panels. Next, lay a second layer of plywood at a 45-degree angle to the first layer.Can you use plywood as flooring?
Planks, squares, and other shapes: Hardwood planks are expensive, but you can achieve that natural woodsy appeal by cutting sheets of plywood into planks, squares, or other shapes, then gluing and/or nailing the pieces to the subfloor. If you buy CDX plywood to finish a 10-foot by 10-foot room, you'd need four ½-in.How thick should Plywood be under tile?
British Standards recommend a minimum of 15mm thick plywood to be used for over-boarding purposes (any less will not provide the rigidity required). This involves screwing a sheet of plywood over the top of the existing floorboards / chipboard or plywood to provide extra rigidity and a flat surface onto which to tile.How much weight can plywood hold?
A 12-by-36-inch piece of 3/4-inch fir plywood can support up to 50 lbs. without problems. Plywood strength drops when thickness diminishes. For example; a 12-by-36-inch piece of 1/4-inch plywood will only support about 5 lbs.What is better for subfloor OSB or plywood?
The National Tile Contractors Association and the Resilient Floor Covering Institute both recommend plywood for subflooring and underlayment, because it doesn't have the risk of swollen edges that OSB does. Plywood also has a slight advantage in stiffness, which means that subflooring panels need not be quite as thick. 
