Attic Conversion Floor Joists

A basic floor system is installed in about 10 stages from preparation to boarding the floor.

Attic conversion floor joists.

All our current 2x6 joist are spaced 16 on center. In the case of 2x6 joists you can pair them up with additional 2x6 joists by nailing them together side by side. We currently have 2x6 floor joist that span 16 on one side and 18 on another. I m wanting to remodel our attic to add a few bedrooms.

The loft room will also have to be separated by a fire door either at the top or bottom of the new stairs. When joists spacings are wider they should be deeper as well to limit stress and deflection under the load. If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists. A new floor system is installed using a frame trimmer joists to support the floor joists that span the width of the loft.

The floor framework is mostly made of wood joints running parallel to one another at regular intervals. There are many ways of altering roof structures for loft conversions but they all have one common element the ceiling joists will almost certainly be inadequate as floor joists. In this video i show how i cut my my joists make packer plates get the joists from the garden up int. Fortunately this is a fairly easy fix.

You might open up your attic and find bare joists with fiberglass or cellulose insulation between the joists. Sistering is the process of adding a new joist next to each existing joist. Clearing the loft area of all debris insulation struts and temporary boards to expose the ceiling boards. Most floor joists are typically spaced 2 by 8s 2 by 10s and 2 by 12s.

This means that new floor joists are fitted alongside them slightly raised above the ceiling plasterboard to avoid contact with it. New homes install i beam shaped joists. This is part 2 in my series of loft conversion videos. You can sister the joists by cutting 2 x8 boards the same length as the joists applying construction adhesive and affixing each to a joist with nails.

The new floor joists of your loft conversion will need to offer at least 30 minutes worth of fire protection which could mean replastering the ceilings in those first floor rooms below.