Loft conversion

[b21playa]

Hi all

I am pondering over the idea of converting our loft to add an extra room and possibly an en-suite. House is a 3bed 1930s semi

The width of the house is 18ft min to 20ft max. (house is stepped half way).

The roof is a traditional cut roof with purlins supporting mid span. Ceiling joists look like 3x2 spanning front to back (approx 28ft), and are supported mid span on a load bearing wall. These are not deep enough to support any load. What would options be for a new floor and how much height would I lose?

 

[freddiemercurystwin]

Typically around 250mm off the floor and 100mm off the roof.

 

[b21playa]

Are RSJ's usually put vertically underneath the purlins, so the load can be transferred?

Also as the purlins attach to the hip, when the roof is converted to a gable end, how are these extended?

 

[freddiemercurystwin]

Purlins are beneath the purlins. The purlins will need to be extended. Its not really a problem as the support for the rafters will be coming off the new steel so the purlins is no longer doing much in terms of providing support.

 

[b21playa]

Purlins are beneath the purlins. The purlins will need to be extended. Its not really a problem as the support for the rafters will be coming off the new steel so the purlins is no longer doing much in terms of providing support.

can the purlins be removed then and re-supported with 4x2 off the steels? Might be easier, with a better finish.

also as i want to change from hip to gable end, is it possible to do this in studwork? will this be ok to hold the roof up?

Thanks in advance

 

[b21playa]

also the ceilings on the first floor are sloped where the wall plates are lower then the ceiling height.

When changing the roof from hip to gable end, will this cause any problems, as I dont want any of the ceiling disturbed inside, as its only been a year since I've completly renovated the house. I understand the hallway/stairs plus 1 bedroom may be affected

 

[freddiemercurystwin]

You would normally put the steels, add your new floor joists and build up the stud walls to support the purlins, then remove any of the existing structure that need to go. Seems pretty simple to me. Normally the purlins are positioned where you would build your dwarf walls anyway so what's the advantage of removing them?

Do what in studwork, the gable end? If so why studwork? Are you building off a traditional cavity wall?

edit: Assuming the existing ceiling/wall/eaves relationship does not need altering the ceilings should be ok bar maybe a little cracking etc. Par for the course with all that activity going on above.