Raising A Roof By Adding A Knee Wall

Raising a roof adding a second floor and creating a vaulted ceiling are all big projects.

Raising a roof by adding a knee wall.

An attic knee wall is a short wall that extends from the floor of an attic room to the roof rafters. If the point at which the knee wall touches the rafter is taken as a support then basically half the roof load transfers but in reality only a part of the load is going to transfer based on the deflection of the rafters. You can t simply add a new wall a knee wall on top of the existing walls. In a framed roof with a knee wall how can one determine the load from the roof through the wall to the floor.

Most of the lifting that will correct your sagging east wall will be from the eastern corners of the north and south walls. In most instances they are no taller than 3 feet but some builders may custom fit them according to the roof s shape and size. Adding a second floor. Inside the garage tack two 12 ft.

You can add anything up to a 2 foot knee wall to the top plate of the garage. This can be done if you are removing the whole roof off of the garage and save the top plate. Raising a roof adding a second floor and. My preference would be to add wood studs or a mini wall or as second choice put in a block knee wall.

Either way you ll need the help of a structural engineer to make it safe. But there s an important structural issue you need to address first. The knee wall forms the wall of the attic room and it also creates an enclosed space under the eaves behind the wall. Roger makes some valid points about raising only the roof.

Unlike other kinds of knee walls this kind of wall extends all the way to the rafters but because of the slope of the roof. Once the ledgers are up drive three double headed 16d form nails through the ledgers into each. The major change is that we lifted the roof 2 feet. Knee walls are short usually wooden walls installed around the sides of an attic where the rafters meet the floor.

From the garage floor. Long 2 8 ledgers to the northeast and southeast walls about 2 ft. Another method is covering the existing wall and new knee wall with full height plywood sheathing to eliminate the hinge. For additional stability you should add a few lag bolts to secure the knee wall and the top plate together.

You can see the image below for an example of a knee wall.