Roof question (felt)

[Barlidge]

I'm in the process of roofing my shed (pics coming soon, I promise) and at the moment it has a temporary covering of DPM over the OSB. Is there any reason not to leave the DPM on and felt over it? Its going to be a temporary first layer of shed felt and then once the weather warms up a bit will be adding torch on. I have no other use for the DPM so would likely go in the bin otherwise

While I'm here any recommendations for a torch on system?

 

[gaz1]

@roofman

i would probably remove the dpm so i can inspect your osb before felting

as goes for torch you will need a few things for it gas govener tuve and also a trigger torch as you need a good flow to melt the torch on before roll out

when trigger is depressed it drops back to a low light so it stays lit while you need to be doing over stuff

 

[Barlidge]

Cheers Gaz, the roof is all new fitted, so new OSB. I do already have a roofing torch, very handy for weed killing the pathways

 

[CornishPete]

While I'm here any recommendations for a torch on system?

I'm a builder and done lots of flat roofs. I wouldn't recommend torch on to anyone compared with the alternatives, GRP and rubber. GRP takes a bit of practice but for a shed I'd personally use (and did) rubber. Readily available at builders merchants, costs no more than 3 layers of torch on and is so easy, perfect for diyers. Will last twice as long and take half the time. It really is a no brainer. And if there's a new OSB deck that's perfect, you're half way there!

 

[Seadog]

I used rubber on my workshop. Fairly easy to do and guaranteed for 50 years.

 

[angellonewolf]

only thing with rubber roof can you put ladder on it ok ? im thinking of my rear roof but when cleaning windows roof problems i might need a ladder on there

 

[roofman]

I'm a builder and done lots of flat roofs. I wouldn't recommend torch on to anyone compared with the alternatives, GRP and rubber. GRP takes a bit of practice but for a shed I'd personally use (and did) rubber. Readily available at builders merchants, costs no more than 3 layers of torch on and is so easy, perfect for diyers. Will last twice as long and take half the time. It really is a no brainer. And if there's a new OSB deck that's perfect, you're half way there!

Ime a flat roofer of almost 45 years being in the game before torch-on was around and your talking tosh..stick to building

 

[roofman]

I used rubber on my workshop. Fairly easy to do and guaranteed for 50 years.

The glues and adhesives wont last half of that, believe me

 

[Seadog]

Ah, but it's nailed down, too.

 

[brightspark]

ive done a few flat roofs years ago with the old tar boiler and felt and done 2 newer ones with torch on felt . its easy once you have done a couple and got the hang of it . its quality and lasts as well its a bonus when you have scored 4 rolls free as well . i bought a roofers torch and gear for 15 quid in mint condition and got another given . use it for burning weeds as well. handy having the economiser trigger and piezo igniter

 

[Barlidge]

Its not a regular shape so with rubber it would be a huge single sheet with lots of wastage off cuts and lots of joints. I'm no roofer but my gut tells me to trust a bitumen base. Its also under trees and will have solar panels up there so there will be some access. The original question was if to lead the temp DPM down under the felt as seemed a waste to throw it away.

 

[roofman]

Its not a regular shape so with rubber it would be a huge single sheet with lots of wastage off cuts and lots of joints. I'm no roofer but my gut tells me to trust a bitumen base. Its also under trees and will have solar panels up there so there will be some access. The original question was if to lead the temp DPM down under the felt as seemed a waste to throw it away.

The answer being yes you can..prime the complete area with bitumen primer and leave for 24 hours to flash off and dry before you start with the torch-on product...we use either Iko or Rose roofing products for many reasons, lets just say they are good

 

[Erie Fred]

I built a tar spraying gun.....

Reflective Coatings - Century Industries Corporation

I was overcoating older metal roofing with the "Fiberized Aluminized roof coating", and a brush or roller wasn't cutting it, it looks terrible.
so I built a gun, found an old 5 gallon pressure pot, and sprayed it on.
Looks much more even.

 

[CornishPete]

Ime a flat roofer of almost 45 years being in the game before torch-on was around and your talking tosh..stick to building

Any system done badly won't last as long as one done well so it's a bit difficult to say one is "better" than the other, or will last longer. As for advice to the op It depends on the situation. I never claimed anything was "tosh" I simply said I wouldn't recommend torch on, and I stand by that. 45 years as a professional flat roofer is not the same as a first time diyer doing a shed, or even myself doing a few a year roofing an extension. I was just offering my opinion. Doing it as part of my work I've found the grp or rubber so much easier than torch on, there's usually uPVC fascias/soffits so the rubber trims looks smarter too.

 

[roofman]

Any system done badly won't last as long as one done well so it's a bit difficult to say one is "better" than the other, or will last longer. As for advice to the op It depends on the situation. I never claimed anything was "tosh" I simply said I wouldn't recommend torch on, and I stand by that. 45 years as a professional flat roofer is not the same as a first time diyer doing a shed, or even myself doing a few a year roofing an extension. I was just offering my opinion. Doing it as part of my work I've found the grp or rubber so much easier than torch on, there's usually uPVC fascias/soffits so the rubber trims looks smarter too.

No offence meant from me fella,just offering my opinion too on your post saying GRP or rubber will last twice as long as a top quality Full SBS torch on system. Anyway its sat, what am i doing arguing about roofs,that's for next week starting Monday at 6.30AM

 

[brightspark]

sig offer 15 years guarantee on torch on felt. it can last up to 25 yeas as well

 

[CornishPete]

No offence meant from me fella,just offering my opinion too on your post saying GRP or rubber will last twice as long as a top quality Full SBS torch on system. Anyway its sat, what am i doing arguing about roofs,that's for next week starting Monday at 6.30AM

I know you didn't and none taken! I realise my summing up remark was a bit flippant, didn't mean it literally! And 6.30 is far too early for us builders!