precast house

wilhelm

Hello all.

2 years ago we bought a house that was constructed using precast panels.

Basically, there are upright precast columns, and hosizontal precast panels are slotted inbetween, much like a precast wall.

When we bought it, we had the single glazed timber windows removed and replaced with new double glazed windows.
When these were being fitted, I had a look at the wall construction, and it is (from external to internal) a precast panel externally, with plywood, plastic dpc sheet, then finally internal drywall.

Over the 2 winters we've lived here, we tend to keep a multi fuel stove going in the lounge, and we've noticed damp patches on the walls which correlate with where the joins are on the panels externally. These are only in the two furthest rooms from the lounge.

Also, we've noticed in the corners where the walls meet the ceilings in the rooms are damp in the mornings.

These issues seem most prevalent when it is very cold outside.

Google has told me about precast concrete homes, so I was wondering....

If I installed vents and got external insulation fitted, would this solve what I assume to be my problems: Condenastion and cold bridging/moisture?

wilhelm

Just to add, the house was built in the mid to late '70's.

BryanF

wilhelm wrote: »

installed vents and got external insulation fitted, would this solve what I assume to be my problems: Condenastion and cold bridging/moisture?
Just to add, the house was built in the mid to late '70's.

Yes imo the Best approach, Ewi beats drylining for insulation continuity hands down. But in a considered manner as part of a holistic insulation, air-tightness/vapour control, rising damp, extract fans in wet rooms, heating/plumbing etc approach

wilhelm

Thanks Bryan.

We are going to put an extractor in the bathroom and kitchen.

I'm going to try and drill though and install vents in the two furthest bedrooms that suffer from the damp spots, then we'll get a quote in to see what the external wall insulation will cost.

I saw on another thread from about 5 years back that it would be in the 100 to 110 euro price range per m2.
Does anyone, for interests sakes and to prepare myself for the shock, know what external insulation fitted would be as a price per m2, as a rough guide?

I fear 2015 is going to be a tough year for me on financial outlay...

wilhelm

Just a follow up on this thread...

I core drilled holes and installed vents in the two back bedrooms mentioned above,...the ones prone to the damp spots/condensation.
It didn't help at all.

So I guess the next step is external wall insulation (EWI).
The mother in law got EWI a while back, and I must say it makes the wall sound hollow and flimsy when you knock on it outside. Hers are expanded polystyrene panels.
Is there a more robust alternative? A different, more solid insulating board other the expanded polystyrene? Something that doesn't make the wall sound hollow and flimsy?
Also, can one get a normal cement render/external plaster applied instead on the lightweight ones that seem to be applied?

Calahonda52

wilhelm wrote: »

Is there a more robust alternative? A different, more solid insulating board other the expanded polystyrene? Something that doesn't make the wall sound hollow and flimsy?
Also, can one get a normal cement render/external plaster applied instead on the lightweight ones that seem to be applied?

There is a solution which uses concrete boards ( sometime called cement boards) on the outside which are screwed to timber uprights: is more labour intensive and therefore more expensive and not found widely here in Ireland.
Will pm u a place where they can give u some more advice.

Its not a normal plaster render over it.

It is a stronger surface that the one ur MIL has but will still sounds a bit hollow.

You CANNOT put normal plaster on the stuff ur MIL has.

wilhelm

Thanks for that info Calahonda52.

oppenheimer1

wilhelm wrote: »

Just a follow up on this thread...

I core drilled holes and installed vents in the two back bedrooms mentioned above,...the ones prone to the damp spots/condensation.
It didn't help at all.

So I guess the next step is external wall insulation (EWI).
The mother in law got EWI a while back, and I must say it makes the wall sound hollow and flimsy when you knock on it outside. Hers are expanded polystyrene panels.
Is there a more robust alternative? A different, more solid insulating board other the expanded polystyrene? Something that doesn't make the wall sound hollow and flimsy?
Also, can one get a normal cement render/external plaster applied instead on the lightweight ones that seem to be applied?

Don't forget there are grants available for external insulation