Attic Insulation again…

March 02, 2011 | Filed under: energy efficiency

Theres some games conference going on, but I’m not there, and it’s very pazazzy, so I thought I’d blog about loft insulation instead. I’m sticking it to the man.

I live in a very old (1750s) house built out of mud and dead peasants, and it’s extremely cold at times. This is because the house was built before mankind invented double glazing, or indeed, glazing, it sometimes seems. Anyway, part of my five year stalinesque plan is to insulate the darned thing, and we are currently working on the attic. the attic is big, has lots of old beams and is about two hundred degrees below zero.

Taking away the side panels to see what was behind them revealed this:

Which is to say mostly 18th century rubble, dust and the remains of fossilised birds nests. Not a completely poor insulator, but not exactly aerogel. Clearly we could do better, but we needed to preserve an air gap to allow air to circulate. These old houses need to ‘breath’. We ended up wedging individually cut pieces of reflective-backed foam insulation between the rafters, with tiny blocks to hold them in place. That felt is all that is between me, and the stone roof tiles, and then open country…

Eventually that was all done on this bit, which is the lower section of a quarter of the half of the room we are currently doing. This will tke years. (we ended up doing a quarter of the attic, to date). a secondĀ  layer of felt goes back, pinned on top of all this.

Then the fun bit, which is laying lots of ‘semi-rigid’ sheeps-woolesque soft insulation between the floor rafters (not visible here), and then laying an additional layer of really wooly even more sheeps woolesque stuff over the top, curved around to prevent any drafts. You can also see a big thick mega-chunky piece of foam insulation that will go in front of all of this, behind the wooden side panels (the panel itself is very thin and crap). The sheeps woolesque stuff was horrid. cue lots of spluttering and itching.

This is everything put back in place, all I need to do now is fill the slight gap where it meets the beam with flexible filler, then I’m going to give the whole thing a coat on nano-paint. it sounds like bullshit, but we used this in our living room and it’s very very good. Basically a nanotech paint additive that reflects heat. great for insulating where cavity walls don’t exist and internal insulation isn’t an option. This is what it all looked like before we started. This time it might be warm though. It’s certainly quieter.

The other end of the room is much much harder to get to, so we are employing someone to come balance on ladders and do that end for us. One day, the temperature of the house will get to the stage where we can have just 2 duvets in the summer. One of the positive outcomes to doing this, is that as I lay there covered in dirt, hammering nails and swearing, I remembered why I gave up carpentry to become a computer programmer. Woodwork sucks. Debugging might be annoying, but C++ doesn’t bend when you hit it.

11 Responses to “Attic Insulation again…”

  1. RodeoClown says:

    Ha!
    Your house is 30-40 years older than my COUNTRY!

  2. kone says:

    Hey there Cliffski,

    my father works as a verfier for also this kind of stuff and an expert for old houses.
    Shall I give him this blog post and ask him if he has any comments?

  3. cliffski says:

    sure, expert opinions very welcome

  4. kone says:

    Cliff, I’ll try translate the (long) answer of my father but it’s not so easy.
    I will try to give you what I understood, you can ask if you have specific questions, I will then try to see more into it.


    This is a beautiful house. Best thing about it are the windows.
    This house has outlasted centuries because air has been flowing around the used natural building materials.
    It’s very dangerous to trap humidity within the wood – that would give spores (I hope this is correctly translated) and dry rot (or boletus destructor) the chance to literally destroy the house in short time.

    What you do want to do using this insulation is to lower your heating costs.
    (But judging by your pictures he goes on to say) that it’s bad for the house.
    Particulary it’s bad to wrap wood (and wooden beams) into wood shavings (or wood wool). If you would like to do it right you need to add a airproof foil on the rafter (?) and the insulation because otherwise the moisture of the warm air will diffuse through the gypsum wallboard. Thats bad because there is a lower temperature there an the dewpoint will be reached. So your insulation itself will get wet. If it gets wet the functionality of the insulation is nullified – your investment useless then.

    (hope it makes sense)

  5. cliffski says:

    hmm interesting. Is that suggesting that you shouldn’t let sheeps wool, or other similar insulation touch the wooden timbers? (without being encased in a foil bag).
    It must be possible to insulate a house constructed in this way. There is still airflow running over the top of the rafters, and inbetween them, but half of the gap is now filled with rigid insulation.
    Presumably air doesn’t have to flow from outside into the house, it just has to flow around the wooden beams?
    Errrk

  6. kone says:

    Sent him your questions…
    As soon as he answers I will translate and post again.

  7. nana says:

    Why on earth did you settle for a house in the middle of nowhere in cold/rainy england :)
    You have lot of money (yes, you do compare to most people on earth) and you have the luxuary to be able to move anywhere in the world and still be able to carry on your work. If the lady is ok, you should travel or at least experience moving abroad for few years before you are getting too old. Seriously, I did it once and I’m planning to do this a second time, and unlike you, I don’t have cats but 3 kids… The life experience you gain from this is priceless and beyond what most people think.

  8. kone says:

    Ok – there it is.
    I really hope that this will bring the message across since I can’t possibly align this perfectly. Also I think that one should clarify which of those house related terms and definitions is the shield, which is the amor, which is the hull and so on so that we could understand this better.

    There are two persuations:
    1. Leave the house like it is. It will hold many more (hundred) years. Don’t try to improve it energetically. There is no law that you need to do it when you have in fact an old house.
    2. Of course you want to live in the house and to live you need it warm. It’s also a habitation quality improvement of course. And you save on heating costs.
    What you need here is, that the insulation and the rafter need to have direct (pressing-) contact – so you wont have cold parts inbetween this.

    The inside foil would be needed to separate the moist compartment air from the insulation. Because of the air is warmer it can store more air humidity, this will cause water to settle on the (slightly) colder insulation and stays there until the insulation is soaking wet with moisture. Then you will get mould fungus.

    If you have an air flow between the roof boarding (also “roof sheathing”) and the insulation then this is okay, because the moist will be transported away.
    If you have this setting, you would need to have a foil in between roof boarding and insulation of the roof boarding (instead of between plasterboard (or “gypsum wallboard”) and insulation). The reason here would be that you would shield the air moisture of the outside air (which flows around the rafter) from the insulation. If you have this scenario you wouldn’t need a foil between the gypsum wallboard and the insulation.
    So you have two different technical solutions for this problem which one shouldn’t mix.

  9. Chris McLaren says:

    One of the reasons Cliffski might be doing this is the home report they made mandatory about 2 years ago. It measures energy consumption as one of the key areas.

    Not sure if this is why your doing this but it is a pain if you come to sell it and the buyer has a report showing him the house is not as economical as newer houses. that said I prefer older houses, built to last.

  10. Garry says:

    I think they scrapped the home report stuff

  11. Happy Days says:

    […] also nice to know I’m not the only indie dev that likes to do a bit of DIY. blog comments powered by Disqus […]