How To Floor An Attic With Trusses

Attic insulation between roof trusses.

How to floor an attic with trusses.

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 inch plywood or. Even easier you can also use a prefabricated attic floor kit designed specifically to raise the attic floor above the insulation. Toenail a truss into the top of the wall plate by nailing through the sides of the bottom chord at a 30 degree angle. If you have attic trusses not conventional trusses the members will be sized to support living space.

Attic trusses are popular over garages or anywhere people want to increase living or storage space without adding another floor to their structure. If the roof slope is steeper than 9 inches in 12 inches of run it doesn t take much width to end up with a nice room 12 feet wide with an 8 foot ceiling. Attic trusses have a rectangular shape inside each truss. Since removing them is clearly not a safe option it s essential to replace them with horizontal steel beams that provide sufficient structural strength for the entire construction.

In the case of 2x6 joists you can pair them up with additional 2x6 joists by nailing them together side by side. The structure should be sufficiently wide to allow for a loft and attic spaces the loft area must be on a living floor and have attic rooms on both sides separated by knee walls a flat ceiling in the loft area and a floor below steep enough roof pitch to provide appropriate ceiling height for the loft area. I have this above my own garage. Given that the w shaped trusses support the loft floor and ceiling structure through their diagonal bracing they don t allow for an open attic space under the roof.

Adding a new floor to weak attic trusses may interfere with the structural integrity of your house and can cause your ceiling to cave in. Certain conditions must be met before an attic truss can be built. As with rafter style roofs toenailing is one of the most common ways of attaching a truss style roof to a wall plate. Use a tape measure to measure the length and width of where you want to place the flooring.

Look at this photo of the space created by attic trusses at my home. If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists. However if you keep the storage weight to a minimum you may be able to build a storage platform above the insulation by attaching supporting beams to the sides of the trusses. Use bracing to keep the trusses in place as you work your way across.

Measure the space where you want to lay the floor. If you have a rafter framed attic the floor joists may or may not be large enough for living space and may need to be reinforced or replaced. Sistering is the process of adding a new joist next to each existing joist. You can t see the floor but.