Metal sheet roof- Condensation

[Andy26]

I've recently re-roofed an old building with box profile tin sheets, (it previously had a corrugated tin sheet roof, that didn't seem to bad for condensation, but was very porous anyhow!).

What options are there?

I guess insulation is an obvious one?

Would improving ventilation help?

Any experiences greatly received.

 

[Davey]

Do you mean instead of the new roof you've just put up or as well as?

If it doesn't need to be metal I'd say plastic was the easiest solution? Otherwise vent at the top to let the warm air out or insulation to keep the warm air inside away from the cold tin roof.

 

[Dry Rot]

Plastic, as suggested by Davey. Builders' damp proof membrane (DPM) fixed to under side of roof timbers with 12mmx50mm battens. Cheap and cheerful and it works.

 

[multi power]

it will be damp now because of lack of ventelation, amazing how much hot air escapes out the holes in an old roof

 

[FonterraFarmer]

Why you not put building paper under new roof? Easy as.

 

[roscoe erf]

tyvek

 

[J B]

I've recently re-roofed an old building

What's the shed used for?

 

[Andy26]

What's the shed used for?

Part of its a small workshop, the rest storing machinery etc.

 

[Tinman Steels Ltd]

The two best options are more ventilation or insulation, we do a anti-condensation backing for the sheets but unfortunately its not a retro fit option as the former actually adds the backing to the sheets as they are manufactured.

 

[Will 1594]

Same problem here. What can be put in workshop roof to stop it dripping

 

[carpenter1]

i am considering a roof for the workshop, is it better to have fiber cement roof instead of box profile? was going to have box profile sides

 

[mo!]

Spray on insulation?

 

[Tinman Steels Ltd]

Fibre cement or Drip-Stop backed Box profile sheeting is good for preventing dripping from condensation but you do need to leave the eaves and ridge open for them to ventilate.

It is more time consuming but the best roof is still a built up system as your have got multiple layers, it offers a better noise reduction and it is warm.

 

[Steevo]

Put some timbers across the roof, and then put another skin of tin on top. If you're feeling really fancy, fill the cavity with insulation.

 

[Hopley89]

if you go for the pre made insulated roof panels they have got sufficient air flow though them to stop condensation build up, have a ventilated ridge with vented soffit for the beat air flow,
but if it's for an open air building where the machinery is stored i'd use a single tin with tyvek and use a insulated multi skin for the work shop.
plastic is way to noisy when raining...

 

[crofter 65]

Fibre cement for a new roof that's whats on my last shed and it seems good, the only down side is the roof lights still suffer condensation.