blackrose Posted June 24, 2017 Report Share Posted June 24, 2017 (edited) I know there's a long thread on the Grenfell tower fire in the VP, but I just wanted to discuss the use of foam insulation on boats. That fire and the revelation that some tower blocks are clad in insulation panels which are combustible and may not meet building regs, has prompted me to wonder about the safety of sprayfoam and perhaps solid polyurethane panels (Kingspan, Cellotex, etc) commonly used to insulate boats. I have PhD in a plastic foam related subject, so I understand that all plastic foams are combustible (with perhaps the exception of a few less common types containing granite additives). I heard that the Grenfell tower was clad with aluminium/polyethylene (PE) foam. I'm not sure why PE was used (perhaps cost?) because most boats are now insulated with polyurethane (PU) which has better insulation properties than PE. I know some older boats are still insulated with expanded polystyrene (EPS) panels. There are also grades of fire-retardant EPS but I suspect most boats with EPS insulation use standard 1" panels. Anyway, fire-retardant foams, as the name suggests, simply extend time to ignition, but they will eventually ignite and combust. So how do we know that a builder or a contractor has used the correct grade of fire-rated foam? All the fire-rated expanding foam I've seen in hand-held cans are pink and don't expand quite as much as the white stuff, but I don't think I've ever seen a pink sprayfoamed boat - not that my observation necessarily means anything. And I don't think boats insulated with rigid PU board are exempt from this discussion. After all, the Grenfell insulation panels were manufactured by Celotex. Obviously the application of sprayfoam or rigid panels to the inside of a steel boat which is then panelled over is completely different to how a 70s tower block is exterior retro-clad, but we still have an air-gap behind the wooden panels on a boat and we still have potential sources of ignition such as 12v cables running adjacent or through the foam which can overheat. I realise this is a can of worms and there are probably no easy answers... Edited June 24, 2017 by blackrose Link to comment Share on other sites More sharing options...
Robbo Posted June 24, 2017 Report Share Posted June 24, 2017 This video may be of interest; Link to comment Share on other sites More sharing options...
GUMPY Posted June 24, 2017 Report Share Posted June 24, 2017 PU foam which is generally what is used in boats carries a class one fire rating that means that it is highly resistant to fire and does not spread flames quickly so should be safe Link to comment Share on other sites More sharing options...
peterboat Posted June 24, 2017 Report Share Posted June 24, 2017 I am getting ready to insulate the broads cruiser and had thought of spray foam, however I have decided on Superquilt as it is supposed to be equal to 80mm of foam plus its easier to use under the floor. Link to comment Share on other sites More sharing options...
WotEver Posted June 24, 2017 Report Share Posted June 24, 2017 1 hour ago, blackrose said: I just wanted to discuss the use of foam insulation on boats. My opinion, based on no knowledge whatsoever, is that by the time a fire on a boat was hot enough to ignite the PU foam it's probably too late to matter. Link to comment Share on other sites More sharing options...
blackrose Posted June 24, 2017 Author Report Share Posted June 24, 2017 (edited) 1 hour ago, Loddon said: PU foam which is generally what is used in boats carries a class one fire rating that means that it is highly resistant to fire and does not spread flames quickly so should be safe There are lots of different grades of PU foams some of which don't meet the relevant fire rating standards and don't carry a class one fire rating. That was my point. Given the scandal that we are now seeing unfolding related to buildings, how do we know that correct grade has been used on boats? http://asfp.org.uk/webdocs/ASFP E-Bulletin Issue 8.pdf Edited June 24, 2017 by blackrose Link to comment Share on other sites More sharing options...
blackrose Posted June 24, 2017 Author Report Share Posted June 24, 2017 4 minutes ago, WotEver said: My opinion, based on no knowledge whatsoever, is that by the time a fire on a boat was hot enough to ignite the PU foam it's probably too late to matter. If the correct grade of foam has been used then that's probably correct, but if a non-fire rated grade was used then that ignition time will be dramatically reduced and it could matter. Link to comment Share on other sites More sharing options...
ditchcrawler Posted June 24, 2017 Report Share Posted June 24, 2017 Well I know what mine is like because I had an exhaust welded into the engine room hatch and welding a piece of 2" pipe through 4mm steel didn't set it alight. My boat is lined with different thicknesses of plywood and I am quite happy that these would be well alight and I would be dead before the foam caught fire Link to comment Share on other sites More sharing options...
Chewbacka Posted June 24, 2017 Report Share Posted June 24, 2017 I don't know for certain, but I cut a bit off the insulation when I bought my sailaway and burned it with a lighter and compared it with normal (not pink) old foam (from spray can). The results were very surprising, and the amount of foul smoke that came off the standard stuff was enough to convince me that any foam repairs would be ONLY fire rated foam. Link to comment Share on other sites More sharing options...
GUMPY Posted June 24, 2017 Report Share Posted June 24, 2017 44 minutes ago, blackrose said: There are lots of different grades of PU foams some of which don't meet the relevant fire rating standards and don't carry a class one fire rating. That was my point. Given the scandal that we are now seeing unfolding related to buildings, how do we know that correct grade has been used on boats? http://asfp.org.uk/webdocs/ASFP E-Bulletin Issue 8.pdf Websters who did Parglena only use class 1 foam, suspect unless you are having a job done on the cheap most companies will be the same. Also have had welding done with foam in place and no fire Article above refers to fillers in cans rather than insulation. Link to comment Share on other sites More sharing options...
Murflynn Posted June 24, 2017 Report Share Posted June 24, 2017 (edited) 1 hour ago, ditchcrawler said: Well I know what mine is like because I had an exhaust welded into the engine room hatch and welding a piece of 2" pipe through 4mm steel didn't set it alight. My boat is lined with different thicknesses of plywood and I am quite happy that these would be well alight and I would be dead before the foam caught fire Similarly on my widebeam insulated sailaway Scouseboat (similar to the OP's) I used a gas blowlamp to make 28mm copper soldered joints adjacent (within 1") to the PU sprayfoam; each joint took a few minutes to heat up and the blowlamp just left scorch marks on the foam. There was not even any smell or smoke which would have been associated with near-combustion. A boat would be burning very fiercely before that stuff ignited. Edited June 24, 2017 by Murflynn Link to comment Share on other sites More sharing options...
blackrose Posted June 24, 2017 Author Report Share Posted June 24, 2017 4 hours ago, Loddon said: Article above refers to fillers in cans rather than insulation. It's basically the same stuff. Link to comment Share on other sites More sharing options...
blackrose Posted June 24, 2017 Author Report Share Posted June 24, 2017 (edited) 2 hours ago, Murflynn said: Similarly on my widebeam insulated sailaway Scouseboat (similar to the OP's) I used a gas blowlamp to make 28mm copper soldered joints adjacent (within 1") to the PU sprayfoam; each joint took a few minutes to heat up and the blowlamp just left scorch marks on the foam. There was not even any smell or smoke which would have been associated with near-combustion. A boat would be burning very fiercely before that stuff ignited. Well, I had some welding done when I was fitting out about 12 years ago and mine caught fire! The welder was on the roof welding in sort section of pipe used as a collar for my gas water heater flue and I was on the inside with a fire extinguisher and I needed to use it! Edit: Granted that I hadn't cleared any sprayfoam away from the edge of the hole as I hadn't cut away enough lining and didn't have room, so perhaps foam against a hot welding rod is too severe a test, but it does make you think. Edited June 24, 2017 by blackrose Link to comment Share on other sites More sharing options...
stegra Posted June 24, 2017 Report Share Posted June 24, 2017 21 minutes ago, blackrose said: It's basically the same stuff. I use both types in building work on a regular basis. I'm a big fan of aerosol expanding foam but it is certainly not the same as two part PU foam. Link to comment Share on other sites More sharing options...
sueb Posted June 24, 2017 Report Share Posted June 24, 2017 When our boat was spray foamed I put the trimmings on a bonfire. The flames immediately kept 6' in the air. Link to comment Share on other sites More sharing options...
nb Innisfree Posted June 24, 2017 Report Share Posted June 24, 2017 2 or 3 coats of emulsion over spray foam would go some way to slow down its rate of ignition. Link to comment Share on other sites More sharing options...
Murflynn Posted June 25, 2017 Report Share Posted June 25, 2017 (edited) 11 hours ago, sueb said: When our boat was spray foamed I put the trimmings on a bonfire. The flames immediately kept 6' in the air. which demonstrates the difference between igniting in-situ foam with one exposed face in still air, and igniting small pieces of the same material onto a roaring fire where all surfaces are exposed. throwing dry leaves on to a bonfire would have been the same, but getting a pile of dry leaves to burn in the first place is quite a different kettle of fish. (why do we refer to fish kettles in the 21st century?). that is why the test procedure must be done in a prescribed manner. Edited June 25, 2017 by Murflynn Link to comment Share on other sites More sharing options...
bargemast Posted June 25, 2017 Report Share Posted June 25, 2017 11 hours ago, sueb said: When our boat was spray foamed I put the trimmings on a bonfire. The flames immediately kept 6' in the air. Nice one, as if the air isn't polluted enough already, it's supposed to be very poisonous too. Peter. Link to comment Share on other sites More sharing options...
system 4-50 Posted June 25, 2017 Report Share Posted June 25, 2017 42 minutes ago, Murflynn said: which demonstrates the difference between igniting in-situ foam with one exposed face in still air, and igniting small pieces of the same material onto a roaring fire where all surfaces are exposed. throwing dry leaves on to a bonfire would have been the same, but getting a pile of dry leaves to burn in the first place is quite a different kettle of fish. (why do we refer to fish kettles in the 21st century?). that is why the test procedure must be done in a prescribed manner. Fish kettles are available on free loan at Waitrose. 11 hours ago, sueb said: When our boat was spray foamed I put the trimmings on a bonfire. The flames immediately kept 6' in the air. How long ago was that? Did you obtain any documentation from your sprayfoamer as to what heshe used? Link to comment Share on other sites More sharing options...
sueb Posted June 25, 2017 Report Share Posted June 25, 2017 About 30 years. We didn't get any documentation with out boat Link to comment Share on other sites More sharing options...
firstboat Posted June 25, 2017 Report Share Posted June 25, 2017 Be careful using spray foam above head height, especially the cheaper DIY stuff, The excess gasses can quickly fall downwards over your face and it can be very irritating to the eyes, even when the foam itself is some distance away. Link to comment Share on other sites More sharing options...
Detling Posted June 26, 2017 Report Share Posted June 26, 2017 (edited) But of the alternatives the only non combustible insulation is rockwool/mineral fibre, but this can absorb moisture and hold it in close proximity to the steel whilst still allowing oxygen from the air to also reach the steel. So we have to choose between a possible fire risk (although I suspect fumes are worse) or sinking/collapsing due to rust. Life is just to short. Edited June 26, 2017 by Detling Phat funger trouble Link to comment Share on other sites More sharing options...
ditchcrawler Posted June 26, 2017 Report Share Posted June 26, 2017 Maybe all the galley cupboards should be stainless steel with stainless steel work tops, the beds could easily be metal framed and lattice based, our bunks Offshore were like that. Formica wall and ceilings cladding that just leaves lose furnishings to worry about and 20 gallons of diesel and a couple of gas bottles. Link to comment Share on other sites More sharing options...
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