Attic Conversion Ceiling Joist Loft Framing

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.

Attic conversion ceiling joist loft framing.

In other words if your attic has 200 square feet over which the ceiling is at least 5. 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. 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. This means that new floor joists are fitted alongside them slightly raised above the ceiling plasterboard to avoid contact with it.

Loft floors loft floor construction. You might open up your attic and find bare joists with fiberglass or cellulose insulation between the joists. Ceiling joists consist of two narrow low grade timbers often bolted together sistered above a supporting wall. Existing loft joists are designed only to support ceiling boards so a structurally sound floor is needed.

At least 50 of the usable area calculated above must have ceilings of at least 7 feet. 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.