Can I use CDX for subfloor?

Although considered an exterior plywood, CDX is often utilized as the subfloor for kitchens and bathrooms— especially for floors destined to be finished with ceramic tiles.

What type of plywood is best for subfloor?

Standard plywood can be used for subfloors, but a better material is 3/4-inch tongue-and-groove plywood subflooring. The tongue-and-groove edges interlock to resist movement along the panel edges and create an overall stiffer floor.

Is CDX good for flooring?

CDX is best for sub-flooring. In such places, it does not get in contact with a lot of moisture, which prevents it from getting damaged. It is also used for roof sheathing. While CDX is strong and will give good results, it is important that you take care of it.

What is best to use for subflooring?

Plywood. Plywood is considered the most popular material used for subflooring, it has been used since the 1950s and remains one of the top choices for contractors. Standard plywood works perfectly fine as a subflooring material, but the best option is ¾” tongue-and-groove plywood subflooring.

Is CDX the same as plywood?

CDX is a type of plywood. Basically, plywoods are thin veneer sheets that are glued and held together with linking plies. Plywoods are known for their strong resistance to cracking, breaking, or twisting. There are different grades/classes of plywood which are represented by letters A, B, C and D.

Installing the Subfloor

When would you use CDX plywood?

CDX Plywood is used primarily by contractors to build exterior walls and roofs. CDX plywood has one side veneer grade “C” and one side veneer grade “D”. The two are bonded together with glue which can withstand a little moisture. The APA would recognize CDX Grade Plywood as C-D Exposure 1 plywood.

Is CDX plywood waterproof?

Keep in mind that this kind of plywood is water resistant, not waterproof, and can still be ruined from a leaking tub or toilet. CDX plywood is often used under shingles and roofing felt, on walls (just behind the siding and insulation), and as a sub floor just under the carpet pad or a tiled floor's durock.

What thickness should subfloor be?

The minimum thickness of plywood for subflooring is about 5/8 inch. Since it does not hold fasteners as well as plywood, OSB must be a little thicker, or at least 23/32 inch. There are several factors that determine what subfloor thickness is optimal for added benefits like insulation.

Is it better to use OSB or plywood for subfloor?

OSB has a lower resale value than plywood due to its lower strength. For this reason, few homeowners prefer OSB in their homes. Apart from costs, plywood is superior in all the other areas, such as the strength of the structure. For this reason, it's a superior material for use on the subfloor.

What size plywood is best for subfloor?

Glue is sprayed between each layer and the sheet is hot pressed. CDX plywood should be a minimum of 7/16 inch thick. The thicknesses are as follows: 7/16-, 15/32- and 1/2-inch-thick panels require joists spaced 16 inches on center; 19/32- and 5/8-inch-thick panels require joists spaced 20 inches on center.

Is CDX or OSB better?

Although some people will ultimately choose CDX, many experts argue that OSB is better overall for roofing. OSB is far less likely to expand and contract when exposed to humidity and moisture, even though it will take longer to dry. With wrapping, though, it can withstand the elements without issue.

Can you use sheathing as subfloor?

Like Sturd-I-Floor, Rated Sheathing may be plywood or OSB. When used as a subfloor, Rated Sheathing typically requires installation of an additional layer of underlayment on top of it before finish flooring can be applied. The underlayment requirements vary depending on the finish flooring.

What is the difference between CDX and ACX plywood?

Since ACX plywood is a higher grade material than say CDX plywood, it is specifically used in cases that require good appearance or a smooth finish, along with durability. Because this plywood is more expensive than other grades of softwood plywood, it is only used where needed, not in all situations.

Should I use treated plywood for subfloor?

There's no need to worry about making treated wood safer that is completely covered in other materials and hidden from access, such as subflooring. Pressure treated wood doesn't release any gases or particulates that could harm you and your family.

Do you nail or screw subfloor?

Ideally, nail down your subfloor using corrosion-resistant nails that will securely hold it in place and last a long time. Screws are a great alternative that you can easily remove, but they are not as sturdy. Screws are superior in terms of reducing floor squeaks, but the installation is slower.

What type of plywood should be used under hardwood flooring?

Hardwood flooring: Plywood is the best subfloor for hardwood flooring installation. CDX plywood ranging from 1/2 to 3/4-inch-thick and rated A/C will serve well for any hardwood flooring installation. Tongue-and-groove plywood is available to reduce squeaks and help the subfloor fit together better.

What is the cheapest subfloor?

Rarely, a prospective homeowner may recognize that OSB is the cheaper subfloor material.

What type of plywood is used for underlayment?

Lauan Plywood, when used as an underlayment, should be Type 1 (Exterior). The best grade is BB and the next best is CC, while OVL (overlay grade) is the minimum acceptable face grade.

Is OSB OK for subfloor?

Around the 1990s, OSB began to make in-roads into the plywood market for subflooring. Most local codes allow OSB to be used for subflooring. It's always best to check with your local permitting office before using OSB for your subfloor. One advantage that OSB has over plywood is its larger formatting.

Do you need two layers of subfloor?

The subfloor has to be attached to the joists, and two subfloor layers glued together or just nailed through to the joists, is no different than one thicker subfloor layer.

Does subfloor need 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. But to start off, we will need to remove the tongue so the plywood is tight with the exterior ICF walls.

What size screws 3/4 plywood subfloor?

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.

Can you use CDX plywood inside?

CDX plywood is classified as an "exposure" type of sheathing rather than an "exterior." This means that CDX plywood should only be used inside or on surfaces that will not be exposed to water once the building process is complete.

Is CDX moisture resistant?

CDX plywood is exposed when it is used, which means that while it is water-resistant, it is not waterproof, and therefore it can only withstand a limited amount of moisture over a short period of time before it starts to degrade.

What does CDX plywood stand for?

CDX signifies class C to D exposed plywood. Manufactures make any type of plywood from several plies pressed firmly together to create a larger and stronger piece of plywood. Plywood usually is available in plies of three, five, seven, and nine, with the most reduced numbers denotes the highest class plywood.