Attic Conversion Ceiling Joist Loft Framing

Joists insulation and boarding.

Attic conversion ceiling joist loft framing.

Existing loft joists are designed only to support ceiling boards so a structurally sound floor is needed. Ceiling joists consist of two narrow low grade timbers often bolted together sistered above a supporting wall. 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. In other words if your attic has 200 square feet over which the ceiling is at least 5.

At least 50 of the usable area calculated above must have ceilings of at least 7 feet. Lining walls and ceilings with a double layer of acoustic plasterboard can also be very effective as can laying a carpet over thick rubber underlay. Fortunately this is a fairly easy fix. 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.

One of the best materials for sound insulation is mineral wool in quilt or batt form which can be stuffed between floor joists or stud work in your loft conversion. 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.