Green Building Forum - celulose, will it compact over time?

Green Building Forum - celulose, will it compact over time? Sat, 25 May 2013 16:29:59 +0100 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17912#Comment_17912 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17912#Comment_17912 Fri, 04 Apr 2008 18:46:38 +0100 Ben celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17919#Comment_17919 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17919#Comment_17919 Fri, 04 Apr 2008 19:15:03 +0100 tony celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17921#Comment_17921 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17921#Comment_17921 Fri, 04 Apr 2008 19:20:23 +0100 Paul in Montreal
Paul in Montreal.]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17936#Comment_17936 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17936#Comment_17936 Fri, 04 Apr 2008 21:47:29 +0100 Bluemoon celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17958#Comment_17958 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17958#Comment_17958 Sat, 05 Apr 2008 11:27:15 +0100 Ben I want breathable walls and plan to use feather edge boards on the outside with a breather membrane. Then the 300mm warmcell with unfired bricks and clay plaster on the inside. Hopefully a low carbon foot print and quite unexpensive to build?!?]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17960#Comment_17960 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17960#Comment_17960 Sat, 05 Apr 2008 11:45:50 +0100 tony
It sounds good I know but in the early days these included a vapour barrier on the warm side of the insulation! now they sometimes specify less resistance all the way out through the wall so make sure your breather layer is not a bottleneck in this process.]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17964#Comment_17964 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17964#Comment_17964 Sat, 05 Apr 2008 12:56:13 +0100 Ed Davies
" That is not the way it is done. The natural settling density
of cellulose is between 1.3 and 1.6 pound per cubic foot. So, by
"Dense Packing" it into walls and cathedral ceilings, at between 3
and 3.75 pound per cubic foot, you can assure that any vibrations
will expand it rather than settle it. It is like an over-stuffed pillow
that will push out its stuffing if ever opened. Over time, it expands
and equalizes, into every tiny crevice in the wall. It expand instead
of settling.

" This, "Dense Pack" technique uses, on average, 2 to 2.5 times
as much material, so it is not without cost, but there are other very
important benefits to "Dense Pack" One is that it seals against air
leakage, close to as well as spray foam insulations, but at a far lower
cost. The other is that it can absorb large amount of moisture without
any significant effect. This also serves to save other materials in the
wall from water related damage. In tests at the University of Colorado,
cellulose was shown to be far more effective than fiberglass of the same
Rvalue (about 25% IIRC). Also while bat insulations, like fiberglass,
rockwool, etc, loose as much as 50% of their 72°F rated insulation
value, as temperatures drop to -20°F, the Rvalue of cellulose actually
increase (~20% IIRC). So, as temperatures drop, and you need
insulation the most, fiberglass performs worse, and cellulose performs
significantly better than its rated RValue.

" In the real world, moisture in walls is a major issue, and the fact
the dense pack cellulose can absorb over a cup of water, per cubic
foot, without even a significant change in Rvalue, make a real
difference, that does not get included in any of the Rvalue
comparison number."

Unfortunately, I left his group early in the year when it got overrun with political comments. Pity as there was good information there.]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17968#Comment_17968 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17968#Comment_17968 Sat, 05 Apr 2008 17:11:01 +0100 Albert >Also while bat insulations, like fiberglass,
>rockwool, etc, loose as much as 50% of their 72°F rated insulation
>value, as temperatures drop to -20°F, the Rvalue of cellulose actually
i>ncrease (~20% IIRC).

Have I been totally unobservant? I'm sure this is the first time I've ever seen a statement about R value varying with ambient temperature. Can anyone explain (in simple terms) the mechanism behind this?

On the general topic of this thread I'd prefer to use batts or sheet material in a new build timber frame, using blown insulation only where access is a problem. Just my opinion.]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17984#Comment_17984 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17984#Comment_17984 Sat, 05 Apr 2008 19:34:03 +0100 Ed Davies
"Have I been totally unobservant? I'm sure this is the first time I've ever seen a statement about R value varying with ambient temperature. Can anyone explain (in simple terms) the mechanism behind this?"

It seems to be to do with convection kicking in at a certain temperature gradient.

http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/92/920510.html]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17986#Comment_17986 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17986#Comment_17986 Sat, 05 Apr 2008 20:43:23 +0100 Albert
Must admit that I'm unlikely to live anywhere with outside temperatures much below zero for any signicant periods so my interest is purely academic.

Edit: Having read it I can see the logic for the convention effect but can't see why cellulose loose fill should actually improve with greater temperature differentials.]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17987#Comment_17987 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17987#Comment_17987 Sat, 05 Apr 2008 21:24:13 +0100 Ed Davies celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17988#Comment_17988 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17988#Comment_17988 Sat, 05 Apr 2008 21:36:21 +0100 howdytom tom]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17989#Comment_17989 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=17989#Comment_17989 Sat, 05 Apr 2008 21:58:19 +0100 tony celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18040#Comment_18040 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18040#Comment_18040 Sun, 06 Apr 2008 20:07:33 +0100 OJ Posted By: Paul in MontrealI'm intrigued that your walls are 12" thick - this is more than twice the thickness of low energy housing in Canada. Sounds like a lot of extra material will be required for little benefit. If you need high insulation levels, use a better product than the cellulose and you'll save in many ways.

Paul in Montreal.

Can you say, Paul, what a "better product" would be in this situation?

Posted By: tony
It sounds good I know but in the early days these included a vapour barrier on the warm side of the insulation! now they sometimes specify less resistance all the way out through the wall so make sure your breather layer is not a bottleneck in this process.

Can you give an example of what you mean, Tony? Are you saying that working to the five times rule for vapour resistance is not the best way to go in a breathing timber wall (not breathing room)? Vapour barrier on the warm side is described in current publications i.e. 2008, not so early days. Who are "they"?

Many thanks, OJ]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18047#Comment_18047 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18047#Comment_18047 Sun, 06 Apr 2008 20:48:22 +0100 tony
When breathing walls were first introduced they too had a vapour barrier. At the time it seemed to me to make a nonsense of the breathing bit.]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18049#Comment_18049 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18049#Comment_18049 Sun, 06 Apr 2008 21:02:17 +0100 OJ celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18076#Comment_18076 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18076#Comment_18076 Mon, 07 Apr 2008 09:30:44 +0100 Johan celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18094#Comment_18094 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18094#Comment_18094 Mon, 07 Apr 2008 16:34:56 +0100 Bluemoon celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18117#Comment_18117 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18117#Comment_18117 Mon, 07 Apr 2008 21:55:35 +0100 Terry celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18144#Comment_18144 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18144#Comment_18144 Tue, 08 Apr 2008 09:32:41 +0100 Johan
Flax based insulation also perform well, like this one http://www.isolina.com/gb/insulation.cfm.]]> celulose, will it compact over time? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18150#Comment_18150 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1535&Focus=18150#Comment_18150 Tue, 08 Apr 2008 11:14:10 +0100 Bluemoon