dry lining or wet plaster?

pegdrums

Hi, how are ye?

We are renovating our house. It is an end terrace, '60s council built bungalow. Currently it has that nasty thin layer of polystyrene on the inside of the external walls. Walls I believe are cavity block opposed to solid block but I need to confirm that. We are in the process of removing all polystyrene plus old wallpaper etc.

Question is what to replace it with?
Wet plaster or dry-line?

Wet plaster is slower, but stronger in the end, nicer finish and has better thermal and sound insulating properties according to what I've read.

Dry-lining is faster, cheaper but doesn't give as nice a finish and is easier to damage and harder to hang shelves etc after, again according to what I've read.

I've been reading about fermacell, any experience with this?

I am reading up on differences but was hoping on some real world advice/ examples.

Front is facing west, side is north, rear South, East is party wall.

Many thanks,
Gavin

Calahonda52

are you talking gypsum skim or sand cement plaster.

Is there a red brick layer out side or just the block?

pegdrums

The outside is dashed over the block. I think they are cavity block because when I hung the gate last year I remember the drill suddenly disappearing into the wall of the house. But I may be wrong.

"are you talking gypsum skim or sand cement plaster."

-Good question

Basically we just want to have nice finished walls that we can come along and paint and be done. Apart from one or two internal walls all of the walls in this house are block.

At the moment we seem to have the original rough finish.

My head is exploding with all the options Im reading about.

board and skim
sand and cement with smooth skim on top
hard coat and skim finish
dry lining

If dry lining is MILES AND MILES cheaper I'll have to go with that but if the difference isn't over the top I think Id prefer some sort of plaster option.

listermint

If your just wet plastering the wall. Where is the insulating properties if your stripping off old polystyrene?

Rather than considering how lovely the finish is. First consider how you can thermal break the wall. Generally this is done with warm board / insulated board. Then skim coat to finish.

pegdrums

So are you talking about something like this:
https://www.soundinsulation.ie/product/mustwall-33b-for-party-walls/
these kind of systems eat a lot of room space. its only a small house.
Fix that to the wall and skim over?

Is it an absolute no no to just plaster directly to the masonry wall?

RandRuns

As with listermint above, I'd be looking at what I have in terms of insulation (very little would be my guess) and going with what gives me the best option.
A 60's council bungalow, if it's in Dublin, is almost certainly cavity blocks, meaning that you've no insulation. The best option (in my opinion) would be external insulation, followed by skimcoating the interior walls. This gives excellent insulation properties and good airtightness (as long as the attic/roof is done at the same time), while not losing any space inside, and minimises the amount of layout changes you have to make.
The second best option (again in my opinion) would be to dryline the interior of the external walls with insulated plasterboard, and then skimcoat - this gives you good insulating and airtightness properties (again as long as the attic/roof is matched), and is a lot cheaper, but also means that you lose some internal space (which can be important in a 60's council house), and may mean some internal rejigging. The walls you aren't insulating (internal partitions) could be just skimmed.

pegdrums

Thanks for the advice.

We did initially look at your first option of external insulation. That is indeed an appealing and less messy option. The other bonus of this would be that we would just have to specify the same skim job for all internal walls. We got quotes ranging from 6-7.5k for external insulation. When you factor in the grant that may actually work out cheaper than insulated plasterboard.
This stuff costs 1.5k roughly for the party walls.
https://www.soundinsulation.ie/product/mustwall-33b-for-party-walls/

I know that's sound insulation but cost per sheet isn't wildly different to thermal. I think.

RandRuns

pegdrums wrote: »

Thanks for the advice.

We did initially look at your first option of external insulation. That is indeed an appealing and less messy option. The other bonus of this would be that we would just have to specify the same skim job for all internal walls. We got quotes ranging from 6-7.5k for external insulation. When you factor in the grant that may actually work out cheaper than insulated plasterboard.
This stuff costs 1.5k roughly for the party walls.
https://www.soundinsulation.ie/product/mustwall-33b-for-party-walls/

I know that's sound insulation but cost per sheet isn't wildly different to thermal. I think.

Just reread your post, and I read "bungalow" as meaning a detached - now I realise it's an eot, then external is definitely the way to go - you only have 3 walls to do, and two of those are single height.
I'd definitely go with external insulation with skimcoat inside.

pegdrums

Just did a rough (!) calculation ....

We have 52 m2 of wall that would need insulated plasterboard.

2.4mx1.2mx 50mm of xtratherm insulated plasterboard = €35 ea.

Total to cover the inside of all our external walls roughly €670 (just for parts)

Why does that sound too cheap? The acoustic insulation for just the party walls was over double that.

Also does anyone know roughly what plasterers are charging nowadays? Is there a cost per m2 or something?

Stihl waters

pegdrums wrote: »

Just did a rough (!) calculation ....

We have 52 m2 of wall that would need insulated plasterboard.

2.4mx1.2mx 50mm of xtratherm insulated plasterboard = €35 ea.

Total to cover the inside of all our external walls roughly €670 (just for parts)

Why does that sound too cheap? The acoustic insulation for just the party walls was over double that.

Also does anyone know roughly what plasterers are charging nowadays? Is there a cost per m2 or something?

52 square meters of wall is only 19 boards, that's 2 days work for a plasterer if everything is ready including beading taping up etc. A plasterer on his own for 2 days could cost between 400 to 600 depending on what part of the country you're in

pegdrums

Stihl waters wrote: »

52 square meters of wall is only 19 boards, that's 2 days work for a plasterer if everything is ready including beading taping up etc. A plasterer on his own for 2 days could cost between 400 to 600 depending on what part of the country you're in

so lets say...
750 all in for parts (boards plus anything else required)

1200 for plasterer (Im in Cork but best over plan) 2 days at 600 p.d

300 - 2 days (?) for the contractor to get the boards up and ready (they'll be on site doing various other things so it'll just be a part of their overall job)

100 or so for contingency

All in could cost around 2.4k .

Roughly speaking.

piplip87

https://www.gov.ie/en/service/home-energy-grants/

I'd take a look here and see if what you want to do is covered.

Government are throwing money at any kind of a retrofit scheme.

Stihl waters

pegdrums wrote: »

so lets say...
750 all in for parts (boards plus anything else required)

1200 for plasterer (Im in Cork but best over plan) 2 days at 600 p.d

300 - 2 days (?) for the contractor to get the boards up and ready (they'll be on site doing various other things so it'll just be a part of their overall job)

100 or so for contingency

All in could cost around 2.4k .

Roughly speaking.

200 to 300 per day for the plasterer, not 600, or if you're paying 600 I'll go down to cork and do it for you :pac:

Allow 800 materials

Allow 400 to slab

Rough estimates obviously but shouldn't be too far off

pegdrums

piplip87 wrote: »

https://www.gov.ie/en/service/home-energy-grants/

I'd take a look here and see if what you want to do is covered.

Government are throwing money at any kind of a retrofit scheme.

Cheers, I've emailed them with a few queries so will hopefully have a few answers to share tomorrow. Coincidentally I somehow found their list of registered installers and that's where I got the quotes but never landed on the main grants page. Lots of useful reading on it so thanks for that.

pegdrums

Stihl waters wrote: »

200 to 300 per day for the plasterer, not 600, or if you're paying 600 I'll go down to cork and do it for you :pac:

Allow 800 materials

Allow 400 to slab

Rough estimates obviously but shouldn't be too far off

So call it 2k ball park.

The available external insulation grant for end of terrace is 4,500. Thats probably for 2 storey not bungalow but if the difference between internal and external was somewhat manageable I might try go for external and skim interior walls.

BryanF

End of terrace 60’s in cork. Is the existing wall insulation, brown in colour, about an inch thick? If so that’s Cork (as in the cork tree/ wine bottle) insulation, and personally I’d leave it and look at the external wall insulation.

pegdrums

We'll have to check wall by wall I think. One wall has nothing at all, one wall has polystyrene glued to it and then one wall in the spare room does actually have a sheet of plasterboard on it. Not sure if it dot/ dab or batonned.
Its a wacky old house!!

Sure the windows are a mix of single glazed wood frame, double glazed wood, aluminium and there's 2 pvc!!