Plumb cut wall out question

[amsie]

Hi all,

Cut a rafter to 10 degrees, offered up to wall only to find the existing house wall is out of level.

My question is for every rafter that is out on the plumb cut should I make an adjusting cut so that the rafter sits square to the existing wall as opposed to just the tip of the timber touching the wall?

Top of rafters to existing house wall will be birdsmouth cuts to wallplate, just doing a test cut on the timber.

Thanks in advance,

Paul

 

[catlad]

You can either true up the wall plate on the house wall, or as you say cut the individual rafters to suite.

 

[^woody^]

I think he means out of plumb, because level won't make a difference

 

[pinenot]

Tell us how did you figure 10 degrees in the first instance?...pinenot

 

[amsie]

Hi guys,

10degrees is the max pitch I can get without having to build the roof around existing windows. Its a single storey read extension with a mon pitch roof.

The wall plate will be 100 x 50, with birdsmouth cuts to the top of the rafter onto the wall plate.

Cheers

Paul

 

[pinenot]

The problem with cutting skew cuts to rafter ends, is that they seldom work out at a predefined angle. What should be done, is a template rafter should be set up in such a way that the cut is marked from the actual wall, this is the true angle, not pre-defined. From this all the other rafters are marked out and cut. The wall board/cleat should be packed in such a way as to be parallel to the eaves wall, or if there is to be an angle between the front and back walls both the first and last rafters should be offered up, marked, and cut, these then form the templates which develop the cuts for the remaining rafters. Insomuch as the difference between first and last rafters is divided up by the number of the remaining rafters to give a series of slightly differing sizes/lengths. The skew cuts and birdsmouths remain identical and any resulting small gaps/discrepancies to the back wall are effectively ignored with the sarking taking a scribe cut as required, or tiles as the case may be. the lead flashing will be dressed and cut to hide all...pinenot