EPDM - Damp Substrate

[the_kilo_1984]

Hello all,

I'm currently in the process of building a garden room which is 4.8 x 3.6m. The plan was for the sips kit to arrive in August to give me some nice sunny weather to build it and get the EPDM roof on. The kit was delayed however and didn't arrive until the middle of November, which meant I only had a 3 day dry window to erect the kit before the rain came in (I live in Scotland, it's been a very wet winter). I used a DPM secured over the sides with battens to protect the roof over winter and it's performed pretty well, allowing me to crack on with the bifold, window and cladding.

My plan was to wait until warmer weather in April or May before fitting the EPDM roof, however today I've noticed a small drip inside the garden room coming from the roof. I climbed up and had a look at the DPM and can't see any obvious tears, however it might just be starting to fail slightly after quite a harsh winter.

My question, is how dry does the substrate need to be when installing an EPDM roof covering? I'm certain that a majority of the roof timber is none dry, apart from this one small section where there is a drip.

Do I need to wait for a week long spell of dry weather (quite rare in Scotland . . ) with the DPM removed to completely dry out the roof timber and sips panels, or will a day of dry weather do the trick?

I'm now quite keen to get the proper roof covering on but I want to make sure it's done correctly. Thanks in advance.

 

[^woody^]

The deck needs to be dry for the adhesive to set. Damp also risks delaminating the deck or blowing it if OSB.

Throw a £20 tarp over it.

 

[omph]

or you may end up with loads of nasty looking air bubbles.

 

[Notch7]

however it might just be starting to fail slightly after quite a harsh winter

I can’t see how EPDM can be failing, other than wind driving rain into somewhere not battened down enough or a puncture.

I had plastic DPM over my garden room for a year, then EPDM for another year and it stayed completely dry, although this is South East not Scotland.


It’s good you e got the EPDM up on the roof, it will have relaxed and lost most of its creases

I would just wait until a period of settled weather, you need sun and wind to dry it.

If when you roll it back and find it’s damp from a bit of Ingres or condensation, you can help it dry out a bit with a roofers blowlamp - that’s what my roofers used before doing GRP