Old 1966 Rofab House

Dave1014

HI Guys,
Looking for some advice on an upcoming project.
We are in the final steps of buying a house.
The house was built around 1966 and is of a rofab design.
The house was basicially put together like Lego peices with concrete posts erected and concrete slabs placed in which constructed the exterior walls.

The house is in fairly good condition inside and outside but is in need of major modernisation!!

The first thing we will be tackeling is putting up insulation.
The first thing I want to ask advice on is:

Should the insulation plasterboard be put straight onto the wall or should I erect some galvinasied stud up and then fix to that? I think that the stud is the better option as this would leave breathing space between the exterior wall and the insulation. This would also create somewhat of a cavity. Should we put up some sort of damp course between the insulated plasterboard and the exterior wall? We will also be insulating the exterior of the house maybe next year.
Would somebody be able to advise.

Secondly,there is tarmac running up as far as the front walls of the house. I have a fear this will create dampness as the tarmac seems to run up to the same height as the floors inside the house.
Would it be best to big out the tarmac around the house and put in a drainage channel running around the house to bring water away and to create another barrier between the house and the ground?

If anybody else has any other advice or experience with Rofab

All advice welcome and thanks in advance
Dave

BryanF

Dave1014 wrote: »

Should the insulation plasterboard be put straight onto the wall or should I erect some galvinasied stud up and then fix to that?

Dave, id recommend you consider external insulation, you can provide more insulation without the risk of due point on the inside of the concrete, you can achieve better thermal continuity, retain thermal mass etc

it is more expensive but in your situation worth IMO

MicktheMan

Dave1014 wrote: »

Should the insulation plasterboard be put straight onto the wall or should I erect some galvinasied stud up and then fix to that? I think that the stud is the better option as this would leave breathing space between the exterior wall and the insulation. This would also create somewhat of a cavity. Should we put up some sort of damp course between the insulated plasterboard and the exterior wall? We will also be insulating the exterior of the house maybe next year.

I'm confused, are you proposing both internal and external insulation?

newbie2013

Dave1014 wrote: »

The house was built around 1966 and is of a rofab design.

Any pics of this design

Dave1014

Thanks for the reply Bryan. We will be doing something with the outside of the house over the next two years, would it be suitable to do both mick?

The house will be cold as it has a BER rating of G!!! We want to make it as comfortable as possible and have no problem spending money where it is needed. Would it cause problems if we were to put 50.5 insulated plasterboard on the inside covering walls and ceilings and then within the next two years, to insulate the outside with 120mm eps?

BryanF

Dave1014 wrote: »

Thanks for the reply Bryan. We will be doing something with the outside of the house over the next two years, would it be suitable to do both mick?

The house will be cold as it has a BER rating of G!!! We want to make it as comfortable as possible and have no problem spending money where it is needed. Would it cause problems if we were to put 50.5 insulated plasterboard on the inside covering walls and ceilings and then within the next two years, to insulate the outside with 120mm eps?

i wouldn't dryline at all

MicktheMan

BryanF wrote: »

i wouldn't dryline at all

agree

newbie2013

BryanF wrote: »

i wouldn't dryline at all

why ?

Dave1014

Photo of house

BryanF

newbie2013 wrote: »

why ?

Mick would you mind? (must log off)

Outkast_IRE

Hard to tell with the pic but is there much of an overhang on the soffit over the wall ?

Dave1014

Would it not be in our benefit to to use insulated plasterboard inside to held contain the heat within the house?
Sorry if it seems like a stupid question guys!
Dave

newbie2013

Dave1014 wrote: »

Photo of house

Jesus thats one ugly house lol.

Dave1014

There is enough of an overhang there to do the outside!

Dave1014

newbie2013 wrote: »

Jesus thats one ugly house lol.

Exactly why we will be doing the outside!!!!
Its an eyesore!!!

MicktheMan

As Bryan said in an earlier post, drylining moves the dewpoint of the wall to the inside and thus introduces the real risk of interstitial condensation and therefore mould growth between the wall and the insulation.
By externally insulating (ewi), the dew point is moved to outside the building and thus no risk.
There are other benefits of ewi such as significant reduction in thermal bridging which should also be considered.

newbie2013

Dave1014 wrote: »

Exactly why we will be doing the outside!!!!
Its an eyesore!!!

Can you not insulate then put stone on. would look nice if this was allowed.

Dave1014

MicktheMan wrote: »

As Bryan said in an earlier post, drylining moves the dewpoint of the wall to the inside and thus introduces the real risk of interstitial condensation and therefore mould growth between the wall and the insulation.
By externally insulating (ewi), the dew point is moved to outside the building and thus no risk.
There are other benefits of ewi such as significant reduction in thermal bridging which should also be considered.

Thanks for that advice Mick, is this something that a confident DIYer can do! I am planning on doing most of the work myself
Cheers
Dave

Dave1014

newbie2013 wrote: »

Can you not insulate then put stone on. would look nice if this was allowed.

Thats what we were hoping to do...but the budget aint that big!!!

MicktheMan

Dave1014 wrote: »

Thanks for that advice Mick, is this something that a confident DIYer can do! I am planning on doing most of the work myself
Cheers
Dave

Not really, it's a specialists job.



And not all the "specialists" know what they are doing so beware.

newbie2013

Dave1014 wrote: »

Thanks for that advice Mick, is this something that a confident DIYer can do! I am planning on doing most of the work myself
Cheers
Dave

Insulation screwed onto the exterior wrapped in large skrim then 3 coats of waterproof gear finished of with paint. IMO, its easy to do for a confident diyer to do.

BryanF

newbie2013 wrote: »

Insulation screwed onto the exterior wrapped in large skrim then 3 coats of waterproof gear finished of with paint. IMO, its easy to do for a confident diyer to do.

have you done it?

newbie2013

BryanF wrote: »

have you done it?

Yes, we have done this in and around the west these last few years. You drill through your insulation, hammer in with the right fittings, plastic is best then you put on a base coat with like a large skrim, think its in meter lengths. Let that set then another coat goes on really thin then a special paint on top of this. However theres a few different finishes like dash/ non painted. Very easy to do if one is handy with a plastering trowel. One thing i should mention though is that make sure to clean your tools throughout skimming the coats on and when finished because once set, your aswell buying a new trowel because the stuff is a nightmare to get off and at 50euro a trowel, they arent cheap.

newbie2013

OP, if you do do this on your own, make sure to put double or treble skrim around weak joints like windows etc.. because you wouldnt want any cracks in this stuff.

Dave1014

Thanks for all of the advice guys

eamon11

hi Newbie,

can I ask what kind of insulation did you use and its cost? And when you say skrim do you mean skim?

no Dave, mine is a very old bungalow. Also it will be all DIY. I have 4 inch thick metre sq polystyrene and am thinking of putting these as external insulation.

thanks a lot,

eamon

Jimmy Garlic

Insulation thins out/flattens over time. The insulation used in these rofab houses was never very thick in the first place. I would imagine that removing the plasterboard on the interior of the external walls, taking out the old insulation, replacing it with new insulation, then covering it all up with foil backed plasterboard would be the most cost effective way to get a decent level of insulation on these old rofab houses. Right or wrong?

BryanF

wrong. Don't grave dig old threads. Thanks