I've ripped off the old gibb and have building paper to wrap around studs and dwangs so the insulation is on the inside. The problem is two corners where there is only 1cm of access. I may have to forget about that?
tweake,
Jun 19, 1:53am
problem is the studs and nogs need to be on the inside too. paper should be between siding and wall. how are you going to do the bottom plate? paper needs to extend past it otherwise water coming down the paper will sit on the bottom plate and rot it out.
jh34,
Jun 19, 2:49am
According to Branz you can retrofit if you keep the insulation dry. I did it a couple of years ago to a south bedroom and I'm doing it again. I have a good paint job and soakers on the outside (it's a weatherboard house). I don't like doing it this way as recladding is clearly better.
"Moisture accumulation E2.3.5 Concealed spaces and cavities in buildings must be constructed in a way that prevents external moisture being accumulated or transferred and causing condensation, fungal growth, or the degradation of building elements."
you might be able to prise the weather board off a fraction to slip the paper past, even if its only up to the nails on the nogs and bottom plate. ie you want the water to drain down and not sit on top of the nogs and bottom plate.
but regardless of what branz say you still have to comply with building code.
mm12345,
Jun 19, 4:12am
Which more-or-less states that such alterations don't need to bring things up to current code, but should not make things worse than they were. The OP is in Chch - I believe that CCC have a special consent exemption in place for retrofit wall insulation and "like for like" reclad work. I've done a non like-for-like reclad to our '60s house (EQ repairs), installing full wall insulation in the process, and a hell of a lot of work was required to meet code.
tweake,
Jun 19, 4:21am
thats the rub. if weather proofing is not done correctly adding insulation makes its worse.
i do actually see a bit in branz article that only houses with building paper should be retrofit with insulation. kinda going against their own advice.
tweake,
Jun 19, 4:22am
sorry for getting off track a bit. whats the issue with the corners? got a pic?
gabbysnana,
Jun 19, 7:08am
i filled mine with spray foam.
jh34,
Jun 19, 7:11am
that's a good idea.
jh34,
Jun 19, 7:13am
where the two walls meet the studs are at 90 degrees so the corners have a gap where the weatherboards meet.
jh34,
Jun 19, 7:24am
Last time i did it you didn't need a building permit (for Christchurch).
One idea (I've thought about) is having built in furniture on the external wall.
I keep a dehumidifier in the bedroom I did a few years back whenever it is damp.
tweake,
Jun 19, 7:38am
i gotcha, the outside corner. you can't fill it with insulation anyway so just leave it empty. normally there is no gap. better to leave it empty than stuff up the moisture control.
bergkamp,
Jun 19, 8:06am
the idea of the building paper in a retrofit situation is that moisture laden warm air from inside does not condensate upon the batts or back of the weatherboard . not to help with weather ingress
I have done this as part of consented work and the CCC required building paper stapled to the inside of the studs
bergkamp,
Jun 19, 8:18am
good stuff , don't forget to look at the electrics and if you are doing the whole house then look at nailing /screwing some of these sheets off as braceline (depending on what was there before ) with some meaty anchors into the founds / sub -floor *1cm ? corner studs? I wouldn't use expanding foam as this will block out all air circulation , just push through your batt off cuts . * sound controls? sound batts /resilient chanel between ext street front walls and internal walls *older house . look at reversing the doors (as it requires lightswith reposition) if they are hung the old way opening into the room . ceilings - always look at option to bring these down if they are deflecting and ugly . look to use "rondo" channel , a lightweight metal ceiling system that is diy friendly
the list goes on !
tweake,
Jun 19, 8:51am
don't do that. insulation value of compressed insulation is poor, don't stuff insulation in. insulation blocks airflow, regardless of what its made from, you need to sort out the building paper side of things. but in the corner you can't. insulation + no moisture control = rot.
expanding foam won't hold water, so if anything its the better choice. but the best choice is do nothing. let the air flow keep the corner dry.
bergkamp,
Jun 19, 9:07am
*expanding foam will trap moisture but worst of all it will stop air circulation . batts will not do this to the same degree . *slightly compressed batts are better than no batts at all * we are presumably talking about a 30s Weatherboard home - not a modern sealed - up home . these are 2 different animals .There is far more air movement within an old weatherboard house . You would never apply the retrofit philosophy to a modern house * the Christchurch city council insisted we use building paper in the retrofit for the reasons I specified .
tweake,
Jun 19, 10:16am
batts will do it the same, how do you think batts works.
your not going to "slightly compress" batts through a 10mm gap. your going to pound the crap out of it.
a wall is a wall. fitting batts in makes it a "modern house".
no shit they insisted. its only one of many reasons you fit building paper.
jh34,
Jun 19, 9:17pm
I'm going to cut out diagonals (4x2) (the dwangs are set off the weatherboard (50mm) but I'll cut them out also.
I had replaced 3 weatherboards due to borer and inside there were 4 dwangs which were shot whereas the rest had a bit of borer or none
johotech,
Jun 19, 9:41pm
Why would you cut out the bracing and the dwangs?
bergkamp,
Jun 20, 8:29am
whoa ! lets agree or disagree . but why the foul language? - the point here is that the council demanded "squares " cut between the studwork - this was not for water ingress .If you have a really old house then this is probably worth doing .
tweake,
Jun 20, 9:09am
my point here is that is bare minimum. its a no brainier that if you can, do it better. its not that hard to do it better.
just because they only say its for one thing doesn't mean its not for other things as well. they only have to give one reason. i doubt they would even dare list all the reasons as that may make them liable if its doesn't work.
your going to get water ingress through the siding, thats a given. so deal with it the best you can to get it to drain out and keep the insulation, and the timber, dry. you no longer have the air flow to just evaporate it out.
jh34,
Dec 7, 6:02pm
I notice where I had a window put in and weather boards replaced either side, the installer has put building paper on the outside. he has ran the paper between the second to lowest and the lowest. The lowest has an impermeable membrane at the back to channel the water out (not that there is a gap).
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