Dormer loft extension/roof query

[TULETT]

Hi all, hoping someone can provide some help please!

I have a loft conversion with dormer window at rear of property. The dormer extends pretty much the whole width of house with approx. 50cm pitched roof remaining either side of dormer.

Do the roof rafters that support the pitched roof either side of the dormer require any mid-span support? There are 3 rafters each side that are approx 100mm x 40mm.

As background I'm asking because am wanting to remove a chimney breast from first floor that terminates at the roof level (chimney stack above roof was removed when the loft conversion took place). When I got access to the top of the stck I noticed that part of the original purlin is still attached to the 3 rafters and appears to be supported by the top of the chimney breast.

Many thanks in advance for any help

 

[Static]

Very little timber in a roof is non structural..
If the chimney supports the old cut purlin then removing it will need additional support for the purlin.

 

[^woody^]

If one end of the purlin is in the wall, and it is only supporting three rafters, then what is holding up the other end of the purlin?

 

[TULETT]

Woody/Static, thanks for replies.

The other end of the old purlin is nailed (literally 1 nail!) into the studwork of the dormer wall.

When building these type of loft conversions, do the rafters for the pitched roof at the side of the dormer normally require additional support somewhere in the mid-span? We are only talking approx. half a meter width of roof

See pics which may give a better pciture than my description (if I managed to upload them properly, darn techonology!)

[/img]//www.diynot.com/network/TULETT/albums/