Wooden or steel purlins?

[Frank_farmer]

cheapest price is where its at everyone spouts quality is best until the prices are in.

we find it with the gardens we do, someone wants a gazebo, we quote a quality one then we get a call, joe blogs is £1k cheaper, we explain that the spec will not come close. we lose the job.

 

[MD @Minshall Buildings]

cheapest price is where its at everyone spouts quality is best until the prices are in.

we find it with the gardens we do, someone wants a gazebo, we quote a quality one then we get a call, joe blogs is £1k cheaper, we explain that the spec will not come close. we lose the job.

........and sadly on it goes, "quality remains long after price is forgotten"!

 

[Al t'bin]

Careful with Z ds in a grain store if you have a drying floor Ive seen them collect dust and moisture in the cup of the Z and rot out in eight years. Also on 20' bays if Z are not angle braced I have seen wind bounce crack all the roof sheets.

 

[David.]

So is anyone prepared to recommend a supplier of GOOD quality timber purlins, regardless of price?
I've got a general purpose shed to do, and am resigned to having zeds because I have not seen good timbers for 20 years. Last timber one we did, 6 years ago, 8"x3" @15fts they have seasoned out so saggy that if I had time I would take them out and start again.

 

[Lazy Eric]

We have a building with wooden purlins at 20ft. Be about 16 years old and not sagged an inch. Was told at the time it was imported timber from Eastern Europe. RE buildings was the supplier. Sorry of no help.

 

[Post Driver]

Can you not get it in C16 or C24?

 

[Pond digger]

Careful with Z ds in a grain store if you have a drying floor Ive seen them collect dust and moisture in the cup of the Z and rot out in eight years. Also on 20' bays if Z are not angle braced I have seen wind bounce crack all the roof sheets.

Good question: if not, then perhaps there's an opening here for a supplier.

 

[dannewhouse]

we bought ours from sharples I think, C16 graded
15 ft 7" x 3" they were pretty good on price and I haven't had a problem with sag yet ... but the sheds only been up 12 month!
the 5" X 3" sheeting rails sagged if we didn't attach the top Yorkshire boarding 1st in the gable ends

 

[goldeneagle]

Shed we erected this year has 9x3 C24 wooden purlins at 18ft centres no real sign of sag on them yet. Old man got us to fit two tie bolts equi distance at the apex in each bay with a packer piece cut to suit from purlin off cuts. This was on the advice of some timber construction body back in the seventies. Takes a minute to cut and fit, but ties both sides of roof together prior to fibre cement being fitted and should help prevent sag. Done this with two other roofs and no issues with sag there.

 

[Blue.]

@RWG Contracts do you know any decent suppliers of slow grown timber?

 

[RWG Contracts]

@RWG Contracts do you know any decent suppliers of slow grown timber?

I don't sorry @eulb

I think to be fair you'll struggle to find it. All timber grown now is fast grown crap

 

[SimonB]

Contact TFC Supplies in Stafford on 01782 791000 for all your timber needs.

 

[tomtom8]

what about angle iron,ive seen older sheds with them.

 

[Forever Fendt]

Shed we erected this year has 9x3 C24 wooden purlins at 18ft centres no real sign of sag on them yet. Old man got us to fit two tie bolts equi distance at the apex in each bay with a packer piece cut to suit from purlin off cuts. This was on the advice of some timber construction body back in the seventies. Takes a minute to cut and fit, but ties both sides of roof together prior to fibre cement being fitted and should help prevent sag. Done this with two other roofs and no issues with sag there.

the sag is not usually down slope it is actual sag below the line of the rafters although your idea is a good one, quality of timber is the main factor what you need is baltic timber a lot slower grown just look at the growth rings on the end

 

[joe soapy]

When fitting purlins, be sure to put them all the same way up, i forget which is the right way

 

[RWG Contracts]

When fitting purlins, be sure to put them all the same way up, i forget which is the right way

I always say Round side up but both sides are round just ones inside a curve ones outside. So they're high so that they sag straight, in theory

 

[joe soapy]

I always say Round side up but both sides are round just ones inside a curve ones outside. So they're high so that they sag straight, in theory

yea, something like that

 

[phillipe]

do you think it would be a good idea to make 20 ft flitch beams ie, 9x2 ,12mm ply ,9x2 ,as in a sandwich,proper strong things

 

[RWG Contracts]

do you think it would be a good idea to make 20 ft flitch beams ie, 9x2 ,12mm ply ,9x2 ,as in a sandwich,proper strong things

Be to expensive. Best way would be glue-lam timber

 

[RWG Contracts]