The major framing of the timber frame house floor platform is complete! All of the sill beams and floor joists are firmly in place, and now we are at the exciting stage of installing our reclaimed tongue and groove subflooring.
Whew.
Here’s a photo update of how things are shaping up at the work site.
That’s going to be one tall little building! Can’t wait to see more photos of your progress.
That’s going to be one tall little building! Can’t wait to see more photos of your progress.
I’m just catching up on your blog so please excuse my selection of the most recent marginally relevant post to comment on.
In an earlier post you discussed various options for insulation in the floor. You rejected cellulose fibre (recycled newsprint) on the basis that it would have to be blown in. I really hope that’s not true as it’s what I plan to use for my floor (in a similar general structure to yours but a bit more “engineered” – probably with OSB I-beams – as I have to get my designe past UK building inspectors).
Cellulose has to be blown into walls and sloping roofs because in those applications it needs to be compressed enough that settlement is not an issue. Where it’s used horizontally I believe that just pouring it in, and perhaps tamping it down a bit, is quite sufficient. So does the builder here:
http://coyotecottage.com/cabin/cabinconstruction/cellulosefloor.htm
I’m not so convinced about his use of peg board below the cellulose – I’m still puzzling about a more substantial option for this application and how to neatly attach it to the joists if there’s insufficient crawl space under the floor.
Might be a bit trickier in your case where you’ve already put the floor down on top but maybe there’s a way to work around that.
I’m just catching up on your blog so please excuse my selection of the most recent marginally relevant post to comment on.
In an earlier post you discussed various options for insulation in the floor. You rejected cellulose fibre (recycled newsprint) on the basis that it would have to be blown in. I really hope that’s not true as it’s what I plan to use for my floor (in a similar general structure to yours but a bit more “engineered” – probably with OSB I-beams – as I have to get my designe past UK building inspectors).
Cellulose has to be blown into walls and sloping roofs because in those applications it needs to be compressed enough that settlement is not an issue. Where it’s used horizontally I believe that just pouring it in, and perhaps tamping it down a bit, is quite sufficient. So does the builder here:
http://coyotecottage.com/cabin/cabinconstruction/cellulosefloor.htm
I’m not so convinced about his use of peg board below the cellulose – I’m still puzzling about a more substantial option for this application and how to neatly attach it to the joists if there’s insufficient crawl space under the floor.
Might be a bit trickier in your case where you’ve already put the floor down on top but maybe there’s a way to work around that.
Hey Ed:
We are doing blown cellulose after all, based on the fact that it’s insulation properties are a lot higher than light clay straw.
I’m not sure exactly what your question is, or if you have one, but our plan is to contain the cellulose with old roofing metal, attached to 2×6 joists attached to the floor platform sill beams. It’s a rather huge 20″ cavity to fill, and will be r-60+ with the cellulose.
Hey Ed:
We are doing blown cellulose after all, based on the fact that it’s insulation properties are a lot higher than light clay straw.
I’m not sure exactly what your question is, or if you have one, but our plan is to contain the cellulose with old roofing metal, attached to 2×6 joists attached to the floor platform sill beams. It’s a rather huge 20″ cavity to fill, and will be r-60+ with the cellulose.
Hi Ziggy,
Yes, a metal bottom to the building sounds like a good idea from the point of view of repelling nibbling boarders. 20″ is good; I have in mind nearly as much – 450 mm so just under 18″.
On the other hand, I’d be very concerned about having a completely non-vapour-permeable layer (metal sheet) in direct contact with the vapour-permeable insulation. The problem is that water vapour will migrate through the cellulose so that, if there was no condensation, the partial pressure of water vapour in contact with the metal will be the same as that inside the house. If the relative humidity in the house is around 50% and the temperature of the metal is more than about 10 °C (18 °F) cooler than the inside air then condensation will happen and there’ll be nowhere for the condensate to go. It’ll probably not take very long for horrible things to grow in the cellulose if it’s permanently damp – even with the borax treatment.
I’d strongly suggest you get some input from somebody local who has reasonable knowledge of building science before doing what you plan.
The sort of thing I have in mind is, top to bottom: cellulose insulation, OSB, breathable membrane (Tyvek or whatever), treated battens, metal lathe (as used to key plaster) but I’m really not sure yet.
Hi Ziggy,
Yes, a metal bottom to the building sounds like a good idea from the point of view of repelling nibbling boarders. 20″ is good; I have in mind nearly as much – 450 mm so just under 18″.
On the other hand, I’d be very concerned about having a completely non-vapour-permeable layer (metal sheet) in direct contact with the vapour-permeable insulation. The problem is that water vapour will migrate through the cellulose so that, if there was no condensation, the partial pressure of water vapour in contact with the metal will be the same as that inside the house. If the relative humidity in the house is around 50% and the temperature of the metal is more than about 10 °C (18 °F) cooler than the inside air then condensation will happen and there’ll be nowhere for the condensate to go. It’ll probably not take very long for horrible things to grow in the cellulose if it’s permanently damp – even with the borax treatment.
I’d strongly suggest you get some input from somebody local who has reasonable knowledge of building science before doing what you plan.
The sort of thing I have in mind is, top to bottom: cellulose insulation, OSB, breathable membrane (Tyvek or whatever), treated battens, metal lathe (as used to key plaster) but I’m really not sure yet.
Is there a community somewhere doing cob building that can be visited or joined?
Is there a community somewhere doing cob building that can be visited or joined?