Corrugated sheet for a roof, second hand... suggestions please?

[jontawn]

Hi All,

After (not very wisely) using plastic roof sheeting to re-roof the garage, and not making sure there was enough overlap it's gone and leaked ;(

anyway. ... as it's not my garage but my folks, I wondered whether anyone had any thoughts on buying used roofing sheets and any thoughts as to where from? I've looked on ebay and not seen a lot.

apologies if this is in the wrong bit of the forum

ta
jt

 

[pedrobedro]

My brother in law got some box section roof sheet offcuts from a local industrial estate. It was going in the skip and there was plenty to do his shed roof and ready insulated. He had to buy his screws though and the tight sod moaned all day about it.

 

[pidgeon chit welder]

Check out your yellow pages for a local buildings materials reclaim yard . they may have used or seconds .

My own bitter secondhand sheeting experience leads me to say bite the bullet and find the local supplier for new plastisol roofing sheets and all the flashings/ roof ridge ..they dont leak nor does the covering peel off and you can put the holes where you need them instead of trying to seal up ones already there or trying to make the joists run along the current holes .

Ask for overlap advice from the supplier , some say only one ridge others recommend two ...depending on the profile.

Getting the roof planes true is where most people fall down and find leaks at a later date. Use several good quality well tensioned stringing lines and a big spirit level etc.

Look seriously at using some double sided sealer tape to actually seal the roof profile overlaps ..this is immensly beneficial if you get rain slashing down at 30 degrees driven by high winds into the open edge as it prevents ingress via the roof.

 

[jontawn]

tensioned stringing lines?

thanks for the advice so far chaps, very much appreciated.

I fear i'll end up having to put new timbers/steels in to support the new roof as its an old concrete garage and originally had an asbestos roof which was replaced (badly) with some alloy/steel which leaked like a good 'un, and this new effort leaks again, however its just seeping in at the joints.

I am tempted (just tempted) to create a ridge-type roof as opposed to flat/gently sloping towards the back, i'll gain head-room (a bonus) and hopefully easier to roof?

tia,
jt

 

[Hitch]

Is it a flat roof, idealy for box profile sheeting you need a minimum or 3degrees iirc.

Did you tape all the joints? And screw the overlaps properly? Usefull install guide here

Some of the suppliers will sell seconds, usualy just slight colour differences, or not coated properly. They are galvd under the coating anyway, so not a major problem

The sheets are not that dear tbh, the link above has a price list on it too.

 

[jontawn]

Nice one Hitch! As the garage isn't particularly long, We may be able to use 3x long sheets which would not only offer rigidity but lots less opportunity for water ingress!

I didn't see that site during my trawls of the internerd!

ta
jt

 

[tux]

My tuppence for what its worth, use the insulated stuff. I have the single thickness non-insulated sheets on my garage and when its cold it condenses so badly that it literally rains inside!
Need to find some way of insulating it now.

 

[brightspark]

My tuppence for what its worth, use the insulated stuff. I have the single thickness non-insulated sheets on my garage and when its cold it condenses so badly that it literally rains inside!
Need to find some way of insulating it now.

if u want something half decent use kingspan or cellotex sheets its not cheap though

 

[Hitch]

Thats what is in the composite panel sheets, bonded to both surfaces.

 

[busastars]

Ive been searching for ages but finaly ebay came up trumps. I got 17 used 2.4 x 1m sheets of box profile fiberglass, looks alot stronger and worth while than the cheap couragated stuff. All in all £35 to my door.

Screws I have just got from Screwfix, 100 for just under £10. I will be eather using cheapo silicone or hard as nails on all my joints then hoping for the best.

 

[Woody.v8]

Id be tempted not to use the "NO NAILS" type products as they don't serve well as a sealant ie. doesn't flex/prone to cracking.

 

[pidgeon chit welder]

tensioned stringing lines?

thanks for the advice so far chaps, very much appreciated.

I fear i'll end up having to put new timbers/steels in to support the new roof as its an old concrete garage and originally had an asbestos roof which was replaced (badly) with some alloy/steel which leaked like a good 'un, and this new effort leaks again, however its just seeping in at the joints.

I am tempted (just tempted) to create a ridge-type roof as opposed to flat/gently sloping towards the back, i'll gain head-room (a bonus) and hopefully easier to roof?

tia,
jt

Tensioned stringing lines... A well tensiond quality nylon builders line
as your first line from back to front along the side wall to get the run and two others middle and farthest side to checked with the spirit level to get the whole roof plane correct .

Those steel support beams ( it is a sectional concrete garage ??) are really needed for not only do they support the roof if it is the type of roof spar I'm thinking of they will also help to hold the walls and stop them falling inwards outwards at the top etc.
There is usually some degree of adjustment where they are fixed to allow you to set the roof plane .

You will need to take the above into account if you make a ridge roof for your likely to push the walls out .


If it is a concrete sectional garage , perhaps also think about replacing the internal & external mortar fillets around the base for they usually need doing when you re roof , paint the area prior to the remortaring with some dilute pva bonder so it sticks well to the base.

 

[metalspanner]

busa, dont use hard as nails, no more nails or anything of that nature, as there is no flex, dries rigid and the contraction between hot and cold will soon wreck the roof.
The silicone approach is far more robust and conducive to being taken apart resealed and put back together again if and when required.

 

[pidgeon chit welder]

busa, dont use hard as nails, no more nails or anything of that nature, as there is no flex, dries rigid and the contraction between hot and cold will soon wreck the roof.
The silicone approach is far more robust and conducive to being taken apart resealed and put back together again if and when required.

You can buy reels of 5 mm wide double side foam tape especially for sealing up the roof sheets , simply make sure sheet is going to fit, raise the edge up and roll out some of the tape on a top profile edge that's going to be covered and then lower the top sheet down and fix in place. Same applies where sheets overlap in length , tape across all the profile surface of the lower sheet about two inches from the edge and add the top sheet .