dandandan

Thanks for this. Very useful.

Yes, I am pretty confident that the problem is moist air condensating on bare steel surface where insulation is missing. I was hoping that by sprayfoaming the gaps I can provide a moisture barrier? Thanks I will get one of those. Do you have a foam recommendation (this? http://www.toolstation.com/shop/p85137).

Yes, I have no idea who did it. The areas of saturated foam are very localised spots. Still strange that closed cell foam can become saturated.

Hello, I couldn't find an answer to this problem so hopefully not repeated elsewhere. We have had the same damp boat for three years and I have decided to confront it, starting with the bedroom (furthest from the burner and so worst). I have taken the bedroom panels off to look at the insulation and it is pretty awful. Sprayfoam of varying thickness all over, down to about 5mm in places, never more than 25mm. The gunnels have been missed entirely down the whole length, both sides. There are gaps where the wall and roof meet (the installer has clearly not got behind the batten here as is evident from rust staining on the foam below). In a few places the sprayfoam has become debonded from the steel especially where the roof meets the wall. In some places the sprayfoam seems to have become saturated and is discoloured (I thought it was closed cell?). Couple of questions: 1) What should I use to insulate the gunnels? Sprayfoam in a can/kingspan cut and stuck down with marineflex and then gaps filled with sprayfoam/something else? 2) What is the best way to build up the insulation thickness where it is very thin? 3) Where water has saturated the spray foam should I remove damaged material and replace or will it dry out? 4) If I patch up parts with sprayfoam will it bond to exiting foam and create a water barrier or will I need to do this on top of the foam with another material? 5) Some of the battens were soaking wet around the screwheads, is there an easy way to prevent this? Countersink and insulate? Thanks for answers to any of these questions and any other advice! Dan