Anti condensation sheet roofing

[ballibeg]

Need to get roof on the workshop and I'm looking at this.

 

http://www.cladco.uk.com/NoConDrop.html

 

It needs ventilation which I can build in. Big question is does it stop drips?

 

Any experience out there?

 

Thanks,

 

Dave

[WeeDee]

Need to get roof on the workshop and I'm looking at this.

 

http://www.cladco.uk.com/NoConDrop.html

 

It needs ventilation which I can build in. Big question is does it stop drips?

 

Any experience out there?

 

Thanks,

 

Dave

 

It has a slightly 'furry' coating on the underside. When normal condensation occurs, the water has to gather to form drips, this coating allows the water to spread over the entire surface instead of gathering on the low edges of the sheet. The ventilation is needed to evaporate the water from the large damp surface, this happens slowly but usually fast enough to have 'capacity' for the next dew point event. Whether it works or not depends on how much condensation occurs versus how much evaporation follows.

[hedgesparrow]

if you want info then go on BFF forum have a sub section all to do with buildings. should get the answers if i remember they did say its not drip proof. hope this helps

[NI Tree]

i would concider insulated tin if you can espical if you can heat it and in the summer it will keep it cooler. and should not be as noisy when it it raining but i have not been able to try it

[ballibeg]

Thanks guys. I'll look into the foam backed stuff.

 

Dave

[Woodworks]

Foam backed is pretty serious money. Cladco is just up the road from me and we have bought lots off them over the years. Always found them very honest and helpful over the phone so may well be worth a call.

[codlasher]

If you are using any type of single layer tin sheeting on a roof you will always have an issue with condensation.

I use Cladco for many jobs and recommend them to clients too. I particularly like their pan tile sheets, these look good and make a new building blend in well.

 

On the condensation issue with non insulated sheets; If you put a breathable membrane such as Tyvec in as an under layer you will remove the condensation issue. Put this layer in over your rafters and then counter batten ready for the Cladco sheets, problem solved! Reason I like Tyvec is that it is grey underside and white topside unlike the competition thus giving a more pleasant view from underneath. Remember to pull the Tyvec tight and a staple gun helps fix this to the rafters.

You can use clear sheets for light too and a perspex sheet can be fixed underneath to provide the condensation barrier. A bit like secondary double glazing.

codlasher

[ballibeg]

Great advice and glad you're rating Cladco. Think membrane the way to go. Just need to get my head around fixing membrane add you describe. Would you use plain sheeting above and board below or can membrane just be pulled tight?

 

Sorry if I'm a bit slow to visualize.

 

Dave

[Woodworks]

I think the build up that codlasher is suggesting is lay tyvec over your rafters then put a batten (probably 2" or 3" x 1" over the rafter and on top of the tyvec then fix you roofing sheets to this leaving a 1" gap between underside of the sheets and the tyvec. In our back shed I just laid polythene over the rafters and put the sheets on top but where the sheets touch the polythene you still get some condensation and where I have used clear roofing sheets the polythene has been broken down with the UV. codlashers idea sounds very good to me.

[muttley9050]

Don't really disagree with codlasher, but IME roofing felt/membrane should not be pulled tight but be allowed to sag inbetween each rafter. This stems from slate and tile roofing, where any water getting through or condensation formed wants to run to the low spot in the felt and hence stay away from rafters where fixing holes in felt are. Also its not necessary to use any larger baton than 1" roofing baton, which these days measures 25mm x 37mm.