Advice to help soothe the stress of an EPDM roof install

[roobsa]

My partner and I are mid self building a relatively large garden room and the roof (8m~ x 5m~) is causing some stress. I'm hoping someone can advise on how to proceed from where we're at.

We had the EPDM laid over the warm roof for nearly a month before we had anything resembling good weather at a weekend (we live in Scotland). We finally got round to tackling it this Saturday just gone but didn't manage to finish it.

The roof build up is as follows (bottom to top layer):

EPDM (stuck down with contact adhesive)
Tissue-faced PIR (mechanically fixed)
VCL
OSB deck

We suspect due to the very late finish on Saturday, some moisture/condensation affected the final section we tackled which led to a few wrinkles where the adhesive didn't stick properly. We managed to pull the EPDM back a short distance undoing this. This is currently where the roof is at as the weather has turned again.

Ultimately we're not sure whether the wrinkling on the final, unfinished quarter of the EPDM is due to the rubber going out of square with the roof as we progressed or if we were stretching it without realising or if we can continue with our current technique to finish it off without permenantly fixing the wrinkles down and ending up with big creases in the membrane.

We'd very much appreciate some advice as to how to progress.

Some photos during the progress:

 

[Alastairreid]

I would have used water based adhesive for the flat area of the roof and contact for the perimeter and any vertical upstand.

 

[martygturner]

I have faced the same issue,rain stopped play, probably not what you want to hear, but.... The pocket marks caused by the pir fixings should have been filled as this introduces stretch points along with the seams of the insulation. When laying epdm its a do it now process not a do it bit by bit as the product heats and shrinks at different rates from glued to un glued. The weights are not helping, again the pressure points trap the membrane and as it heats a cools it stretches in different directions.

I found the only way to sort out the majority of our wrinkles was to re fold the membrane back over the done bit after allowing air pressure to do its job, well sort of then re lay it back over the new section before refolding it loosely back ready for gluing.. Re-laying took 4 people helping, pulling at the corners and sides to tug out as many creases as possible keeping the membrane just above the glue and working down, found that a wide broom worked best. Used a heat gun...gently.. to attack any blisters. used rollers - the ones for wall paper, bit of drain pipe as a rolling pin or in short anything that that got it as flat.as we could. Ours was badly creased as it had to wait 3 weeks... the result was ok but the amount of faffing ...

Unfortunately as moisture was underneath we ended up with with a fair few bubbles forming over time..its down on a list to redo...

 

[^woody^]

TBH, for a flat roof like that it should be foolproof.

Let the membrane relax for 30 minutes or so over the whole area, the transport wrinkles should disappear.

Only then ....

Fold half back and roll the water-based adhesive on the deck - its white so you can see any missed spots and roll out any thick areas so it's all even
Wait the specified time then carefully slide (don't lift or stretch the folded section of membrane) - it tends to move itself, but help it with a broom and don't let any wrinkles or bubbles form while its being laid.
Repeat the other half
Contact adhesive for the edges or fit the trims

You won't get those bubble out now, unless they disappear of their own accord

 

[Notch7]

I found laying the rubber out flat for a few hours in full sun works a treat in getting rid of creases from being folded up.

I thoroughly vacuumed the roof and the EPDM before laying

I glued both roof and EPDM with waterbased glue, contact adhesive 6” around edge

And a Karnedeane roller

https://www.amazon.co.uk/Karndean-Roller-Extendable-Extends-Professional/dp/B009G7PCT2/ref=asc_df_B009G7PCT2/?tag=googshopuk-21&linkCode=df0&hvadid=696285193871&hvpos=&hvnetw=g&hvrand=3152239033610543606&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9193689&hvtargid=pla-2281435179258&psc=1&mcid=0157204c189e30fba20cc39881bf36d5&hvocijid=3152239033610543606-B009G7PCT2-&hvexpln=74&gad_source=1