Strengthening Roof Joists For Loft Conversion

Trussed rafters loft conversion.

Strengthening roof joists for loft conversion.

It is at this stage when the dormer windows are being constructed that your loft conversion will be exposed to the elements so you ll need good temporary sheeting to protect against the weather. Floor joists even if the loft was previously used for light storage you will almost certainly have to strengthen the ceiling joists in the loft floor. Shafix design install 1 504 034 views. If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists.

I have consulted a structural engineer and he has advised me that the loft joists are not strong enough to handle it and will need strengthening. Developed by a team of engineers and designers the loft leg is strong. Most roofs built from the late 1960s onwards are of prefabricated trussed rafter construction with distinctive w shaped webbing. A 175mm loft leg fixed on top of a 100mm truss or ceiling joist provides a lightweight cost effective solution.

Sistering is the process of adding a new joist next to each existing joist. The plan is just to put down some 18mm chipboard insulate the roof and board off the roof and eaves. You can do this by adding larger and stronger timber floor joists between the existing ceiling joists. A ridge beam is installed beneath the apex before the dormer roof joists can themselves be fixed in place and the roof weathered.

This is part 2 in my series of loft conversion videos. Lightweight and manufactured in the uk from recycled polypropylene to iso9001 standards and has been mechanically tested by independent experts. In this video i show how i cut my my joists make packer plates get the joists from the garden up int.