Saturday, 31 December 2011

dormer construction

it is now time to open the roof and construct the dormer, unless you have a tin roof on your scaffold i would urge you to do this on a dry day!!! also before you open the roof, make sure your pad stones for are cast and ready to accept the rsj for the ridge.

most loft conversions consist of a rear dormer, with this in mind we are only going to strip out the back section of the roof, this is quite straight forward, just remember to prop up the rest of the roof before you start cutting out struts, purl-ins and rafters. when the section of roof is removed install this final steel, normally directly underneath the existing ridge.

the timber work for a dormer construction is usually completed in a day, it is advisable at this stage of a loft conversion to have a professional roofer on hand to help keep the property water tight. construct the dormer walls in the same way you would construct a stud wall remembering double timbers round doors and windows.  once  the walls are up we can now put on the flat roof of our loft conversion. bolt a timber into to rsj under the ridge, place jiffy hangers at 400mm centers on to this timber. now we are going to place 6x2 timbers into these jiffys across and onto the dormer wall running parallel.

to complete this stage of the loft conversion place firrings on top of the 6x2s, a layer of 100mm celotex and then deck the roof in 18mm OSB.