Change in pitch - 30s roof frame


Postby mortarboard » Wed Aug 13, 2008 2:57 pm

I need to match my existing house roof for the front corner of an extension. The existing roof is old clay tiles at 45 degrees but the bottom 9 rows flare out at a shallow angle over a wide soffit. A lot of the local houses have this type of roof (1930s). It looks like a simple 45 slope in the loft so there must be some extra bit on the edge or something. Can anyone tell me where I might find a diagram of the structure to make this corner? Even just the name of the feature would be helpful at this stage! Many thanks
mortarboard
Posts: 36
Joined: Tue Jun 17, 2008 5:29 am

Sponsor

Simply Build It

Postby chris_on_tour2002 » Thu Aug 14, 2008 4:56 pm

unlikely you'll find a diagram. it was probably done with a tapered run of timber fitted to the trusses. could be wrong but that's how i'd do it.
chris_on_tour2002
Posts: 1023
Joined: Thu Aug 30, 2007 9:14 pm


Postby LCL » Thu Aug 14, 2008 9:30 pm

mortarboard

This is a fairly common feature, they are rafter spockets, rafter arms or rafter feet bolted or screwed to the existing rafters. The rafters will bear onto the wall plate as normal and then the sprockets are screwed to the sides of the rafters to form the low level detail. When you open the roof up you will see this. It should be quite simple to replicated.

Hope this helps.

LCL
LCL
Posts: 139
Joined: Tue Sep 11, 2007 2:40 pm


Postby mortarboard » Fri Aug 15, 2008 6:03 am

Thanks for that LCL.

I'm not going to open up the old roof because this will be a completely separate new section at a lower level. But from what you and chris_on_tour2002 are saying it sounds like I should use standard rafters sitting on my wall plate. Then add a horizontal piece that sticks out to form the wide soffit. Then fill in the shallow angle at the bottom with a short slope that tapers back up onto the main 45 degree rafters - forming a small triangle on the outside at the bottom.

I assume I can fix these extra bits onto the main rafter with coach screws?
mortarboard
Posts: 36
Joined: Tue Jun 17, 2008 5:29 am


Postby mortarboard » Fri Aug 22, 2008 8:20 pm

Just an update if anyone was interested...

I have been given an old book called Building Construction Volume One by W B McKay (1938) and this has some very detailed diagrams of my exact feature on P139.

It's pretty much exactly as described by the help here - so thanks!
mortarboard
Posts: 36
Joined: Tue Jun 17, 2008 5:29 am


Display posts from previous
Sort by
Order by


 


  • Related Topics