Roof timbers

Superdaddy

Building a storey and a half house, pricing the roof at the moment. I'm going for a warm roof with a zinc style standing seam metal roof. Roof pitch is 40 degrees. Engineer has done drawing for pricing. He has specified rafters are to be 225x44 @ 400 centers. All the roofers I've talked to say its overkill and will cost a fortune. Said as much to the engineer but he's sticking to his guns. None of the roofers I've spoken to have ever used 225x44 as rafters. Any views?

Gumbo

Superdaddy wrote: »

Building a storey and a half house, pricing the roof at the moment. I'm going for a warm roof with a zinc style standing seam metal roof. Roof pitch is 40 degrees. Engineer has done drawing for pricing. He has specified rafters are to be 225x44 @ 400 centers. All the roofers I've talked to say its overkill and will cost a fortune. Said as much to the engineer but he's sticking to his guns. None of the roofers I've spoken to have ever used 225x44 as rafters. Any views?

Do as the engineer says. Otherwise what's the point of his engagement.
I've seen 225 joists on single storey extensions here in Dublin.

BryanF

come now that's a structural question and you know we can't discuss it here.

Superdaddy wrote: »

Building a storey and a half house, pricing the roof at the moment. I'm going for a warm roof with a zinc style standing seam metal roof. Roof pitch is 40 degrees. Engineer has done drawing for pricing. He has specified rafters are to be 225x44 @ 400 centers. All the roofers I've talked to say its overkill and will cost a fortune. Said as much to the engineer but he's sticking to his guns. None of the roofers I've spoken to have ever used 225x44 as rafters. Any views?

ask your roofer does he carry PI insurance for design advice.

mykillokneel

Can't give structural advice as pointed out but just to tell you as a roofer I've used 225x44 (9x2) rafters on a good few houses especially on longer rafters also alot of attic trusses are made from it

Tefral

8/10 of the last houses I have priced have specified these sized timbers!

Ill give you a point though, Engineers tend to be a little cautious, speaking as a QS ive seen a few places where we have value engineered some stuff for clients after approaching the Engineers as some of the stuff we thought was overkill too. However, the Engineer is ultimately responsible and if they stick to their guns you have to go along with it as they are signing off your design.

Superdaddy

Really only wanted to know how common place their use is in roofs, I know it's the engineers call. Good to see it's not unheard of.

hexosan

I used it in my roof and to be honest theses very little difference in the cost between 9x2 and 7x2 rafters.

rampantbunny

Have them in mine.
Originally had 7 x 2 @ 300mm centres. Saved money in the end changing to 9 x 2 @ 400mm centres because less of them. Haven't done the calcs but the bottom line is the bottom line.