Wasps and SIPS

[Countrypaul]

We recently had 2 wasp nests that I thought were just under the roofing underlay (Proctor Roofshield) getting in at the corner of the main roof (tiled) and flat roof (EPDM) of a dormer. The roof is made of 175mm polyurethane SIPS battened and counter battened with clay tiles.

I thought the wasps were not a problem until they started to appear in my sons bedroom, one morning 12 appeared within an hour. I found a small pile of chewed PUR beside the thermal store (adjacent room to his) but, as is always the case, where this comes from is very difficult to access. I had the two wasp nests destroyed since it meant either climbing up a ladder on to the flat roof to treat them or working off a ladder I did not fancy the job (no protective clothing and no lance to apply any material meant it was easier and safer to get someone in. Called them around 09:30 they called me back 09:45 and arranged to come aroun 16:00. but called back again at 11:00 and agreed to come immediately (located in next village and had to pass anyway). He treated both nests and next morning no sign of any wasp activity.

Access is restricted due to a plywood panel above/behind the thermal store which is fastened to a frame suporting the SIP roof and filled wth rockwool around the MVHR piping to an outlet in his room. There are also 4 water pipes to/from the thermal store in front of the panel and MVHR pipes plus some cables clipped to the panel. The store is the largest we could get in that location (made to fit) and is tight against the sloping roof. Removing the panel to try and view the exact location of where the chewed PUR came from is therefore not really feasible (the thermal store would require moving which means the door and door frame would need removing, the system draining down (430L store + header) pipes disconnecting, carpet lifting etc.

What damage are the wasps likely to have done? Am I likely to have a compromised amount of insulation resulting in significant heat loss? Or is it likely they made a small hole right through the SIP? Is the nest likely to be above the panel and below the tiles with some exploritory hole around? Anyone come across this with SIPS before?

I know wasps can eat though timber, PUR, even plasterboard and various other things. I have no idea how big the nest was just a small access hole that was continuously busy. NO signs outside of any chewed PUR material, but that might no mean anything.

[spread-tee]

I've seen quite a few wasp nests over the years some quite large, 40cm dia or so, but so far I have never noticed any damage to the structure of the building. On removing a nest from a timber there is no signs of chewage or borings, they just seem to stick the nest material on with a bit of spit I think, scrape it off and the wood looks as good as ever.. If you ever pick up an abandoned nest it weighs almost nothing, and most of that material will be scavenged from rotten wood in the locality, I see them scratching about in our wood pile quite regularly.

Deps