Insulating solid brick walls with no cavity - House built in early 1900's

Phil1969 · 21-11-2023 11:46AM #1

I am going to be renovating an old house soon and I was looking to dryline the exterior solid brick walls with insulated plaster boards but after a bit more research it seems that it would not be good for the solid brick walls as they need to breathe?

So, would it be better to place 10cm batons on the walls first then insulate with mineral wool and then plasterboard them? Oh, would it be better to plaster the walls and not insulate them at all?

I have looked into do EWI but it is way over my budget and it would not look good due to the house being semi detached.

Thanks

monseiur · 21-11-2023 06:09PM

You could dry line the 'external' walls using say 50 or 60mm insulated slab board and skim/plaster. Avoid cold bridging at windows.

listermint · 21-11-2023 06:11PM

https://www.boards.ie/discussion/2058323560/insulating-solid-brick-walls-with-no-cavity-house-built-in-early-1900s

How old, what do you mean by solid brick? Is there a cavity? What does the external makeup of the walls look like?

Phil1969 · 21-11-2023 06:14PM

https://www.boards.ie/discussion/comment/121396983#Comment_121396983

Double brick with no cavity.

listermint · 21-11-2023 07:00PM

Cavity brick or solid brick. Double brick implies some Cavity (gap at least)

Phil1969 · 21-11-2023 07:05PM

https://www.boards.ie/discussion/comment/121397168#Comment_121397168

I was told solid brick with no cavity as the house was built in early 1900's.

listermint · 21-11-2023 07:17PM

You main issue will probably be cold bridging rather than damp.

Two things to tackle in separate ways.

1. Cold bridging avoid any sort of dot and dab. You'd want to mechanically fix boards. That's means you can either fix treated battens to the walls and affix your boards to that (insulated) or use cold bridging specific fixings for insulated boards direct to the brick. Particular attention to foaming any areas to prevent cold spot cavities.

2. Ventilation. Really important to ventilate the room to the outside. Most important is to ensure ventilation is properly sleaved through the wall so it doesn't vent behind your boards or into any brick voids. You could also ventilate vertically in ceilings with various mhrv options.

Controlling the moisture levels and eliminating thermal bridging are the two most important things.

From an external perspective its important to make sure gutters are working and fascias and roof fixings are solid. Avoiding unnecessary water ingress into the wall itself is vital too.

Calahonda52 · 21-11-2023 09:34PM

https://www.boards.ie/discussion/comment/121397186#Comment_121397186

You need to establish this beyond "were told"

You need to drill the wall starting on the outside so you know you are drilling brick

Its there a DPC?

what sort of floors are there?

https://www.boards.ie/discussion/2058323560/insulating-solid-brick-walls-with-no-cavity-house-built-in-early-1900s

neither proposal will allow the wall to breath

Phil1969 · 23-11-2023 03:02PM

https://www.boards.ie/discussion/comment/121397228#Comment_121397228

Thanks for the info. I will check the walls properly once I get the keys for the property as we are waiting to complete.

Ventilation is on our to do list, thanks again.

Phil1969 · 23-11-2023 03:05PM

https://www.boards.ie/discussion/comment/121397734#Comment_121397734

Thanks for the advice, we will check the walls as you mention once we get in the house as we are waiting to complete. There is no damp proof course but we are planning to get that sorted. I am not 100% sure on the floor yet so I will need to check that out.

Thanks for the reply.

chooseusername · 23-11-2023 03:31PM

Is this the house? If so, the walls look to be solid stone, rendered on the outside

Phil1969 · 23-11-2023 05:36PM

https://www.boards.ie/discussion/comment/121405224#Comment_121405224

yes it is

Phil1969 · 23-11-2023 07:47PM

https://www.boards.ie/discussion/comment/121406070#Comment_121406070

Does having render on the external wall make a different to what you would use on the interior wall for insulation? thanks

Dr Turk Turkelton · 23-11-2023 07:56PM

https://www.boards.ie/discussion/comment/121397186#Comment_121397186

A house built in the early 1900's with brick will probably be one brick thick. This means approx 9 inches.

It will be more than likely Flemish bond or English bond to tie it together.

Modern walls which are normally built in stretcher bond are normally a half brick thick- approximately 4 inches.

Phil1969 · 23-11-2023 08:10PM

https://www.boards.ie/discussion/comment/121407114#Comment_121407114

Thanks, that gives me a better idea of what I need to be checking for when it comes to insulation for the walls.

chooseusername · 23-11-2023 09:02PM

https://www.boards.ie/discussion/comment/121407040#Comment_121407040

I'm not qualified or experienced enough to advise, I've never dealt with solid stone walls, which is what I think you have.

Here's an old thread, brief and to to the point;

https://www.boards.ie/discussion/2057716453/advice-on-solid-stone-wall-insulation

I think @MicktheMan is still about.

Calahonda52 · 23-11-2023 09:29PM

https://www.boards.ie/discussion/comment/121405224#Comment_121405224

Where is the brick?

chooseusername · 23-11-2023 09:45PM

https://www.boards.ie/discussion/comment/121407942#Comment_121407942

I don't see any brick, I see a stone gable wall in the loft in the surveyor's photos;

Calahonda52 · 23-11-2023 09:49PM

https://www.boards.ie/discussion/comment/121408105#Comment_121408105

The ? was to OP, you have good mince pies!

Calahonda52 · 23-11-2023 09:52PM

There is no damp proof course but we are planning to get that sorted

How exactly because thats another swamp filled with snake oil sellers

This ain't no technological breakdown, oh no, this is the road to hell

https://www.youtube.com/watch?v=gUUdQfnshJ4

My go to for this sort of building is a fully breathable EWI solution along with MVHR

MY preferred EWI has a ventilated cavity behind a cement board rain shield, very important these day with the advent of more driving rain as per the new charts for Ireland.

fully breathable IWI works as well but not my preference

MHVR removes all the moist air and the WI, if chosen wisely will absorb moisture excesses from the walls and release them slowly

A 600mm by 600mm french drain, dug with care and attention to existing foundations and having proper drainage , if any ids another key piece when no DPC.

IMO any solutions offered other than cutting one in with a diamond blade on a chain saw is no better than botox injections

Phil1969 · 24-11-2023 12:19PM

https://www.boards.ie/discussion/comment/121408176#Comment_121408176

Thanks for all the info, I will get a few builders out to take a look and see what they say. Thanks for your advice.

Insulating solid brick walls with no cavity - House built in early 1900's

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