How to install attic floor for storage

If your attic joists won’t bear the weight necessary to finish out a living space but the engineer cleared them to support floor decking for light storage, you can install ½-inch plywood or oriented strand board (OSB) in 4-foot-by-8-foot panels over existing 16-inch OC joists.

An attic can be floored with 1/2″ CDX plywood, if it is being used only for storage. However, the same can‘t be said if you are planning on using the space as a living space. In that case, you will need to use 3/4″ thick plywood. The building code allows for the use of OSB in place of plywood for subflooring.

While attics can be turned into makeshift storage units, most of them are not suited for large, heavy objects such as furniture or temperature-sensitive items like electronics or documents. Always choose the right storage space for the right item in order to avoid any headaches later on.

Since attics are outside the “living space” of your home, they’re an important part of your home’s structure, making adding a floor no simple task. These are raw, unfinished, unheated and uncooled spaces where one false send you flying through the ceiling of the floor below.

Joist Spacing and Attic Use

You need 3/4-inch plywood. The thinner plywood is acceptable when the joist spacing is 16 inches. If you plan to finish the floor in the attic and turn the room into a living space, however, you should always use 3/4-inch plywood.

As long as they are not damaged, the joists should be strong enough to allow you to move around in the attic for an inspection and to provide storage for typical boxed items. The joists should support your weight, but the space between them almost certainly will not.

Sizing the Plywood

No matter what the spacing is on your ceiling joists, 3/4-inch plywood should be used if you plan on walking on it. If you plan on placing the plywood around the perimeter of the opening or door and using it only to store light boxes or materials, 1/2–inch-thick plywood should suffice.

A contractor will charge $550, which includes labor and material, to lay a plywood floor in an area approximately 10-feet square. If you have basic carpentry skills and tools, you can do the job for $190, the cost of the plywood and screws.

Find or buy 1/2-inch plywood or particleboard sections. It’s possible to use other materials, but plywood or particleboard on sale is likely to be less expensive than other wood materials or products. Installing plywood, for example, will create a smooth floor to lay carpet in the future.

Attic Flooring Cost

The cost of attic flooring ranges from $3,000 to $16,000, depending on what you already have. The existing floor joists may not support weight, so you’ll probably need most of these services: Price to replace floor joists: $1,000-$10,000. Cost to install subfloor: $500-$800.

Hellrazor is right, MDF is not rated for flooring. But in addition to plywood you can also consider OSB- same strength as plywood and is likely a little cheaper.

The joists are what support the weight. An uninhabitable attic not designed for storage can handle a 10 pounds per square foot live load. An uninhabitable attic designed for limited storage can handle 20 pounds per square foot live load.

Attic Joists for Live Loads

In many cases, ceiling joists for deceased loads are designed to carry 10 pounds per square foot (psf), as opposed to the 40 or greater psf that live-load joists must carry.

Roof Rafters or Trusses

Another factor that determines whether you can convert your attic is the presence of roof rafters vs. roof trusses. Traditional rafters look like triangles; trusses look like triangles with smaller triangles inside of them—the boards forming these small triangles are called chords and webs.

Cheaper option. Gilbert says that while most attics can, technically, be converted under current building regulations, 95 per cent of the work he has done falls into the more popular and cheaper option: an attic room that is considered a storage rather than a habitable space.

Attic Insulation Costs

According to Home Advisor, insulating your attic can cost between $1700 to $2100. The main factors that impact the cost are: Type and material of your insulation. Square footage of your attic.

Remodeling your attic can boost your home’s resale value—and make it more functional for you now.

According to the NAR 2019 report, converting an attic to a living area nets an average 56% ROI, a higher return than adding a new bathroom, or more than adding a new master suite.

Most homeowners who remodel their attic find it is worth the investment. Even if the home is not put up for sale in the ensuing years, remodeling the attic provides more usable space without adding to the property. This means your property taxes will stay the same unless you rent the attic to a tenant.