What Should I Consider When Renovating Attic Floors?
The attic of a residential home is many times forgotten space. In a colonial or cape design, this space can be substantial, and can offer storage as well as living space potential. What is the best construction procedure to gain usability of this space?
Access into the attic is the first consideration. Is there an attic stair, which would be the best way of entering the space, or is there a pull down stair. A pull down stair is basically a hatch that is framed into the floor of the attic space. This hatch is pulled down from the second or third floor, which will expose a pull down stair. This pull down stair will allow the resident of the home to access the attic space.
In some instances, there is only an attic panel that opens up to the attic space. The use of a ladder to get up into the attic is required. If this is the case, then the owner of the home should consider the installation of an attic pull down stair. This installation is a simple and straight forward process, that will allow easier access to the attic.
Procedure for installing a pull down attic stair.
1.) The stair package can be purchased from any of the building supply stores. The package comes in various sizes and I would recommend the largest size possible for the space you will be accessing the stair from. Normally this is the hallway or closet of the floor directly below the attic space.
2.) Clear instructions will be included within the stair package for installation, however the following steps will be required.
a.) The stair installation will require that an opening in the attic floor be framed in. What this entails is the cutting of one or two of the attic floor joist, which are the ceiling joists of the floor below the attic. The cutting of these members will require you to temporarily support the attic floor.
b.) Prior to cutting any of the joist, you should make a temporary support out of 2X4’s that will rest on the floor of the floor below and firmly wedged under the ceiling sheetrock. The best method for performing this is to create a tee out of a long 2X4 and a short one. The short one should be cut to a length that is long enough to support however many floor joists are being cut. Two of the tees should be constructed to support the opening being created on both sides of the hatch. The tees if properly cut should be wedged under the ceiling to firmly support the floor joist that need to be cut.
c.) Once you are secure that the attic joists are supported, the sheetrock can be cut out of the opening that the hatch will fit into. The best approach to cutting the sheetrock is to use a jig saw or a fine hobby saw, cutting from the attic space down between the floor joists. If there is no access to the attic, then there is no choice but to cut from the bottom up.
d.) Once the sheetrock has been removed, the attic floor joists can be cut as required. There will either be ( 2 ) cuts if only one joist is cut or ( 4 ) if there are two joists.
e.) The cut ends of the floor joist will then have to be, what is referred to as headed off, with a piece of framing the same size as the floor joist. Normally the framing is nailed into the open ends of the floor joists, however I prefer the use of a wood screws, because by using screws the pounding and hammering is eliminated.
f.) Once the framing for the actual stair has been prepared, the hard part is completed. The attic stair package is then inserted in the framed opening and secured as required by the instructions for the stair. Normally the actual stair package is screwed into the framed opening.
The end result will be a simple and convenient means of accessing the attic space.
Of course, if there is room for a full staircase, this should be considered. Access to a large attic is extremely valuable especially if a staircase is built. The room required most cases, would be an area approximately 4 feet by 14 feet. The actual opening can be determined by the height that the stair will have to service. If the home has standard 8 foot ceilings then, the actual height that the stair will need to service is close to 9 feet, due to the framing of the attic floor. A normal stair has a riser slightly less than 8 inches and a tread depth of at least 10 inches. The actual height required to be serviced in inches is divided by the riser height. This calculation will determine the number of treads which will be required which when multiplied by the tread depth of 10 inches, will indicate the length required of the actual attic opening for the stair. The width should be a minimum of a 36 inch tread. The area required for the staircase has now been determined.
It is highly recommended that a stair, if the room is available, be constructed to access the attic space. The ability to have a staircase to the attic is a desirable condition, and will allow the entire attic are to be used for storage or as another living area.
Once the access to the attic is obtained, then the actual construction of a floor within the attic is the next consideration.
There are several different methods and materials that can be used to provide a floor in the attic. I would recommend that any additional insulation be installed prior to the addition of flooring in the attic space. Some considerations and thoughts regarding the installation of an attic floor;
1.) Should additional insulation be installed prior to the installation of a hard surface in the attic? This is a homeowner’s choice, however this is a perfect time to install additional insulation within the attic floor to increase the overall R value of the home. The R value is a means of measuring the amount of insulation and its overall effect on the entire homes heating and cooling needs.
a.) Additional fiberglass batt insulation can be installed between the floor joists of the attic. Consideration must be made to the depth of the attic floor joists and the resultant space provided by the floor joists, for insulation. Fiberglass batts are not meant to be squeezed into a space. The insulation works properly when in a static state, meaning there is no compression of the fiberglass due to squeezing a batt, that is too thick, into a smaller space. If additional insulation is required within the attic, consideration should be given to a secondary framing system installed over the top of the attic joists. Of course this will reduce the amount of headroom available within the attic.
b.) Additional blown in insulation, whether it is cellulous insulation, fiberglass or some other synthetic material that is capable of being blown into the floor joist spacing. Again, as with the batt insulation, the space for the insulation is necessary for the insulation to properly function. A secondary framing system can be installed over the existing, however, this will limit the headroom in the attic.
c.) Spray foam insulation. Technology has advanced the spray foam insulation product to the extent that the spraying of the material in the attic can provide a tremendous increase in the R value of the attic floor, without the need for excessive space. Spray foam that is a closed cell material does not require a vapor barrier and can be installed easily, by a contractor, into the space between the floor joist. The disadvantage of spray foam is the initial cost, however the increase in the insulation rating, as well as the sound and structural stiffness improvements enhancing the use of the attic in many instances will offset the cost factor.
d.) Spray foam in the actual roof rafters of the attic. This is an entirely separate topic and will be further discussed in another article on this website, however for this discussion, the application of spray foam in the roof rafters will offer the home owner an attic environment that is well insulated and usable. However, the venting and placement of vapor barriers is intrinsic to the success of this application and must be carefully understood. It is important that prior to the decision to spray foam the roof rafters a professional construction consultant be involved with the decision to ensure the proper placement of vapor barriers and spray foam insulation.
e.) Foam board or insulation board. The installation of separate pieces of rigid foam board or insulation board must be installed by a contractor that understands the importance of proper placement of the vapor barrier. If the foam board with a vapor barrier is placed at the bottom of each floor joist space, it must be installed with the vapor barrier facing down, always to the warm side. Additional foam or fiberglass insulation can be placed over the top if the vapor barrier is in the correct location. Incorrect placement of the vapor barrier could trap moisture and cause mold and environmental issues.
2.) Once the insulation issue is considered and resolved, the next consideration is the type of attic flooring to be installed over the attic floor framing.
a.) If some type of additional framing system was used to provide additional space for insulation in the attic floor, this additional framing system must be adequate to accept the new attic floor. In most instances, the spacing of the attic floor framing should not exceed a maximum of 16 inch on center spacing. What this refers to, is the actual dimension between the center to center spacing of the supporting framework. This is important. Any flooring system must be adequately supported structurally to provide a proper and usable floor.
b.) If there is enough headroom in the attic space which is based upon how the attic will be utilized a subfloor can be installed. The subfloor can be a plywood sheathing panel, a ply-score panel, or any of the several new subfloor sheathing panels that are on the market. The best subfloor in my opinion, is a ply-score panel of 5/8 inch material with a plugged and sanded second panel installed perpendicular with the bottom sheathing. Both panels should be glued and screwed to one another. This will allow the installation of whatever type of flooring selected on the top of the subfloor.
c.) Once the subfloor is installed, a new wood floor of oak or other selected material can be installed. In addition, vinyl tile, masonry tile, or any laminate flooring can be selected. The key to the success of the floor, is a proper subfloor, once this is in place, any type of finish floor will provide longevity and aesthetic appeal.
d.) If there is no room for a subfloor, or if the area is to be used only for storage, then the installation of plywood or ply-score sheathing will be adequate. The only consideration is the support of the floor on the floor joists. If only for storage, small pieces of sheathing can be installed to facilitate a small budget, and provide support over the attic floor for storage.
The installation of an attic floor simply for storage can be accomplished in many different ways, with many different materials. What are the key concerns when simply trying to install a surface that will support storage.
a.) Make sure whatever is installed is well supported by the attic floor framing.
b.) If required the installation of pieces of wood, screwed to the sides of the floor joists can increase the bearing surface of the floor onto the support floor joists.
c.) Do not simply lay the sheathing, or other product to provide a surface onto the floor joists. The material must either be nailed or screwed down to ensure that the material does not slip off the floor joists and cause a safety issue.
d.) Try not to cover areas that will eventually require additional insulation. If the budget does not allow the added insulation at the time of adding surface in the attic, don’t cover these areas.
e.) Do not install the sheathing or surface material to close to the eaves of the home. In most cases, the proper ventilation of the attic space is provided through openings in the eaves and overhangs of the home, do not cover these vents.
f.) Use material that is strong enough to support a person on the surface. Remember, even if you are slipping the material to be stored onto the attic floor without stepping up onto the floor, the flooring should be installed adequately to support a person. Someone will eventually be walking in the attic and safety is a primary concern.
The attic space in any home is a valuable space that can be utilized for storage and or additional living area. The proper installation of a flooring system will allow the homeowner to utilize this valuable space. If the space is covered by the roof, you are paying for the space! Utilization of all the covered spaces within the home will enhance the resale value as well as provide an easier living environment for the inhabitants.