[Strawbale]lime and earth plaster
rene.dalmeijer at hetnet...
Mon Oct 4 03:10:22 CEST 2004
At 07:36 AM 10/2/04, you wrote:
>We are renovating an old house and have plastered our walls with earth
>plaster. Most of the walls contain tubes witch are connected to our
>central heating system. The walls itself are made of f brick as is the
>foundation. We have a lot of moist climbing up from the walls and some
>areas won't dry.
This is a serious problem not only for the building but also regarding the
health of the occupants you should do something about it.
1) Ideally drain the foundation with a drain pipe at the base of the
brickwork foundation. At least try to find out why the surrounding ground
is so wet. If it is due to a high water table then it will be very
difficult to deal with by drainage only.
2) Basically what is most probably missing in the building is a decent
"Dutch term- Trasraam" this consists of a few courses of brick work around
ground level which have been baked at a high temperature making them much
less hygroscopic. Another additional measure is using special mortar that
is also less hygroscopic thus creating an even more effective water
barrier. Obviously these measures are difficult if not impossible to apply
to an existing building. Various measures are available though for
retrofitting such a problem, though the first option mentioned, drainage is
by far the best. Most are based on impregnating the brickwork with some
kind of proofing goo making it less permeable. This is mostly expert work
and difficult to execute yourself.
3) Ventilate and aerate the brickwork. This requires perforating the brick
work just above ground level with a regular pattern of deep holes d=15-30mm
at roughly 300mm centers. The holes have to be plugged with perforated
covers to prevent critters crawling in. The holes should be angled upwards
to allow rain water to drip out otherwise you could advertently cause frost
damage. Drilling should be done with care to avoid excessive damage to the
>There seems to develop some white powdery fungus on the
>lower part of some inner walls. We thought about stripping the lower part
>of the wall and use a lime plaster instead. Would this solve our problem?
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