Extra insulation

[Summersaltsi]

Morning

I have a new spray foamed sailaway and was wondering if there is any reason not to put celotex or Rockwool on top of this for extra warmth and sound proofing.?

I can't think of any reason not to.

 

Thanks

[Robbo]

Morning

I have a new spray foamed sailaway and was wondering if there is any reason not to put celotex or Rockwool on top of this for extra warmth and sound proofing.?

I can't think of any reason not to.

 

Thanks

 

I have the same as in a spray foamed "shell", I'm adding Rockwool (80kg/m3) mainly for sound insulation (spray foam is really bad at sound insulation), but it will be more effective at stopping sound getting out rather than from in!.

[Machpoint005]

 

I have the same as in a spray foamed "shell", I'm adding Rockwool (80kg/m3) mainly for sound insulation (spray foam is really bad at sound insulation), but it will be more effective at stopping sound getting out rather than from in!.

 

In terms of measuring its sound transmission loss it makes no difference at all which is the 'noisy' side and which the 'quiet' side. You may be confusing the issue with the effects of different acoustical conditions inside and outside the boat.

[bottle]

Morning

I have a new spray foamed sailaway and was wondering if there is any reason not to put celotex or Rockwool on top of this for extra warmth and sound proofing.?

I can't think of any reason not to.

 

Thanks

 

There is no reason not to but you will probably be wasting your money if, the existing sprayfoam has been done correctly and is approximately 50 cms (2 inches) thick.

 

Thicker insulation is a losing battle as the extra thickness required to improve the insulation properties is something like twice the thickness for half the gain, or something like that.

 

There will be someone along who knows, soon.

 

Celotex, if you decide to go ahead, would be better than Rockwool.

[Robbo]

 

 

Celotex, if you decide to go ahead, would be better than Rockwool.

 

I think Rockwool would be better at sound insulation, but not the normal Rockwool, the 45kg/m3 or more stuff.

 

In terms of measuring its sound transmission loss it makes no difference at all which is the 'noisy' side and which the 'quiet' side. You may be confusing the issue with the effects of different acoustical conditions inside and outside the boat.

 

More than likely, it was from a forum comment a while back someone suggested.

[Radiomariner]

 

There is no reason not to but you will probably be wasting your money if, the existing sprayfoam has been done correctly and is approximately 50 cms (2 inches) thick.

 

Thicker insulation is a losing battle as the extra thickness required to improve the insulation properties is something like twice the thickness for half the gain, or something like that.

 

There will be someone along who knows, soon.

 

Celotex, if you decide to go ahead, would be better than Rockwool.

I think you mean 50mm! To be honest, most spray foam lined boats I have seen fall well short of this, varying between 5mm and 20mm. Which, in my opinion does very little more than, when adhering to the steel properly, reduce condensation.

Yes extra insulation will certainly help. Sorry can not advise on best type. All I am sure about is that rock-wool is pretty poor once it is soaking wet, and will not recover well once dried out. (Experience). Water ingress in a boat can come from many sources. If you go for 'wool-like' material make sure it is encased in a watertight jacket

[peterboat]

I have sprayfoam plus 38mm of 3m thinsulite glued to roof and wall panels my boat is very warm

 

Peter

[Ex- Member]

I think you mean 50mm! To be honest, most spray foam lined boats I have seen fall well short of this, varying between 5mm and 20mm. Which, in my opinion does very little more than, when adhering to the steel properly, reduce condensation.

Yes extra insulation will certainly help. Sorry can not advise on best type. All I am sure about is that rock-wool is pretty poor once it is soaking wet, and will not recover well once dried out. (Experience). Water ingress in a boat can come from many sources. If you go for 'wool-like' material make sure it is encased in a watertight jacket

 

That's not correct Rockwool should dry out, it of course needs to be exposed to the open air to do so effectively. The old typr fiberglass wool sometimes called Rockwool is the one that won't recover. I've seen many a boat with a soggy dollop of insulation in the bottom of linings. Rockwool batts are formed in resin so keep their form.

[Radiomariner]

 

That's not correct Rockwool should dry out, it of course needs to be exposed to the open air to do so effectively. The old typr fiberglass wool sometimes called Rockwool is the one that won't recover. I've seen many a boat with a soggy dollop of insulation in the bottom of linings. Rockwool batts are formed in resin so keep their form.

Yes, you are correct. I was referring to the fiberglass type wool. (Usually Pinkish in colour, Still available). Non the less, drying out still necessitates removing panels etc. Always best not to let it get wet!

[dmr]

 

In terms of measuring its sound transmission loss it makes no difference at all which is the 'noisy' side and which the 'quiet' side. You may be confusing the issue with the effects of different acoustical conditions inside and outside the boat.

 

"Reciprocity" to use the technical term. In industry, when measuring these things it is sometimes more convenient to measure the "wrong way round" and as you say the answer is the same.

 

...........Dave

[Ex- Member]

Yes, you are correct. I was referring to the fiberglass type wool. (Usually Pinkish in colour, Still available). Non the less, drying out still necessitates removing panels etc. Always best not to let it get wet!

 

I've just looked up the batts we purchased and used in our boat, they don't actually soak up water at all, looking at other Rockwool stuff even the flexy roll stuff seems to have a very high level of water resistance.

 

Certainly with the old fibreglass roll there must be a lot of boats out there with next to nothing in the way of insulation left if they started out with the fibreglass stuff.

 

http://www.rockwool.co.uk/products/u/2011.product/9847/building-insulation/rockwool-prorox-slab-range-(formerly-known-as-rwa45-rw3-rw4-rw5-rw6)

 

Water Repellency

The ROCKWOOL® Slab Range is highly water repellent. Where it is necessary to maintain water repellency subsequent to heating at elevated temperatures, the use of WRG grade slabs is recommended.

[Summersaltsi]

Thanks for the comments, I will check the budget and the spray foam thickness.

 

Ta