Should I remove cement pointing first before install IWI?

[HCHOC]

Hi
First time buying a semi detached Victorian house in London, I'm buying from a housing association, the house looks ok from first glance, but many issues were revealed during the L3 survey.

My biggest issue is that the whole house is having cement pointing and cement plinth. At the rear, ground floor is also having cement render with some small cracks around the window frame. The cement pointing and plinth seem to be intact for now.

I have about £45k left after completion, and want to use this budget to do some initial refurb. A lot of things need to be fixed, major things are: missing floor covering on first floor, stairs. Small radiator leak and causing some floor boards rotten, some window frames need to be fixed(original sash window, so the wooden frame need a bit fix)

As it's a semi, I understand that I can't put big wardrobe against external wall as it will cause damp. Initially I want to do IWI, floor and loft insulation, ChatGPT tells me it's going to cost £25k+ plus(wood fibre or swip). So I want to do just the IWI and the fixes mentioned above.

After learning about the pointing, I'm
not sure if I can do IWI without fixing the pointing first. ChatGPT says I should do repointing first. I'm a bit stuck as I don't know who I can ask about these questions(please don't laugh at me for asking ChatGPT)

I can live with cosmetic issues, but I want to fix the house properly.

May I ask the forum:
1. Is it true I should only do IWI after cement pointing removal? I'm planning to do rear extension in 2 years time, should I leave the render alone or remove it now?
2. How should I spend the £45k budget to start the initial round of refurb and repair?

Thank you so much for reading my post. I'm very new to this and really want to do things properly.

 

[skierhughes]

Others will be able to give you better help on some of your questions, but I saw this bit -
"major things are: missing floor covering on first floor, stairs."
We have no floor coverings in our house, downstairs is a mix of tile and wood, upstairs and the stairs all wood.
OK, we have a couple of rugs, but I wouldn't call no floor coverings a major problem.

 

[HCHOC]

Others will be able to give you better help on some of your questions, but I saw this bit -
"major things are: missing floor covering on first floor, stairs."
We have no floor coverings in hour house, downstairs is a mix of tile and wood, upstairs and the stairs all wood.
OK, we have a couple of rugs, but I wouldn't call no floor coverings a major problem.

I mainly mean the stairs, it's kinda rough, definitely need some repair.. also added a picture of the window frame.

 

[skierhughes]

Depends on your taste.
A fair bit of work to have nice wooden stairs, but a fair bit of work to prepare for carpeting.
Nothing I would class as needing doing first, but then if they are at our house, my wife would have them at the top of the list.
I'd be classifying as wanting to be done, but there are other things which need to be done first by the sound of your post.
You need to find a really good tradesman who is used to working on an older property, so they have the knowledge to do the work. Often you'll find these cost more per hour, but take less hours, the work is far superior and doesn't need any further attention.

 

[fernicarry]

Window case, at least from what the pic shows, doesn't look too terrible. The part that has come away is a piece of the parting bead which I suspect is a repair piece that just hasn't been terribly well attached. Its just a push fit into the groove in the pulley stile but as its so short if might not get much purchase but it might be a sign that the pulley stile is a bit soft and itself needs repair. Replace the full length, readily available from online sellers.

The brush strips aren't the most attractive but those can be changed for ones where the brush is incorporated into the staff bead (the part that they are screwed to) and they become close to invisible. Similarly you can get parting beads with a brush strip incorporated into them. If you don't want to tackle yourself there are plenty of man-and-van outfits that do that sort of sash window refurbishment work.

So far as IWI and pointing. Ideally yes get the outside of the wall performing properly before doing anything that reduces the breathability on the inside. However if you don't currently have any damp issues then you should get away with doing the IWI inside first. You might need to live in it through some bad weather to answer whether or not you have damp issues however.

But in terms of bang for buck loft insulation should be your first port of call. Especially if there is none or little there now. You're only looking at a few hundred in materials. IWI is a much bigger task and bear in mind that you will have to remove and reinstate decorative details on the external walls like skirting boards and cornices.

 

[jamest]

Regarding IWI, I imagine that a lot depends upon what kind of insulation you're planning to use. The types of system in which there is a narrow, airtight cavity between the wall and vapour impermeable insulation (or indeed any system that uses vapour/water impermeable insulation) doesn't require that the wall allow moisture to escape from the inside to the outside, so re-doing the pointing wouldn't be necessary. However, such systems are not advisable for solid walls, I wouldn't use one. I would use wood fibre or cork with lime plaster. Such systems usually come with the recommendation that the wall behind the insulating layer be vapour permeable and I guess these are the ones that fernicarry has in mind. For these systems, what fernicarry said and you should also strip existing paint and plaster from the walls if they are vapour impermeable.

 

[HCHOC]

Window case, at least from what the pic shows, doesn't look too terrible. The part that has come away is a piece of the parting bead which I suspect is a repair piece that just hasn't been terribly well attached. Its just a push fit into the groove in the pulley stile but as its so short if might not get much purchase but it might be a sign that the pulley stile is a bit soft and itself needs repair. Replace the full length, readily available from online sellers.

The brush strips aren't the most attractive but those can be changed for ones where the brush is incorporated into the staff bead (the part that they are screwed to) and they become close to invisible. Similarly you can get parting beads with a brush strip incorporated into them. If you don't want to tackle yourself there are plenty of man-and-van outfits that do that sort of sash window refurbishment work.

So far as IWI and pointing. Ideally yes get the outside of the wall performing properly before doing anything that reduces the breathability on the inside. However if you don't currently have any damp issues then you should get away with doing the IWI inside first. You might need to live in it through some bad weather to answer whether or not you have damp issues however.

But in terms of bang for buck loft insulation should be your first port of call. Especially if there is none or little there now. You're only looking at a few hundred in materials. IWI is a much bigger task and bear in mind that you will have to remove and reinstate decorative details on the external walls like skirting boards and cornices.

Thank you so much for spending time replying to me with this thorough advice! Highly highly appreciated! Because the house belongs to a housing association, I think they have used the cheapest material possible for the internal paint, I'm quite confidential the paint are not vapour impermeable. Also, there's a lot of imperfections on the wall, so I'm planning to remove all of it. I'm planning to use all breathe-able material. It's very encouraging to hear the news about the window frame! I'm also planning to sand them and repaint all of it. Hope it's not too expensive, but as I understand, it's not urgent.

London was quite sunny for the last month, I believe when the surveyor conducted the L3, it was sunny for a couple of weeks, no damp was detected apart from the radiator leaking bits.

I'm going to properly fix loft insulation. Do you think I should also use wood fibre for loft insulation?

 

[HCHOC]

Regarding IWI, I imagine that a lot depends upon what kind of insulation you're planning to use. The types of system in which there is a narrow, airtight cavity between the wall and vapour impermeable insulation (or indeed any system that uses vapour/water impermeable insulation) doesn't require that the wall allow moisture to escape from the inside to the outside, so re-doing the pointing wouldn't be necessary. However, such systems are not advisable for solid walls, I wouldn't use one. I would use wood fibre or cork with lime plaster. Such systems usually come with the recommendation that the wall behind the insulating layer be vapour permeable and I guess these are the ones that fernicarry has in mind. For these systems, what fernicarry said and you should also strip existing paint and plaster from the walls if they are vapour impermeable.

I think I'm going to use wood fibre. Previously I was considering SWIP, but I think it uses mineral wool. I'm extremely terrified for any fibre glass like material, I'd rather have slightly worse performance than any fibre glass like material. Then I'll use lime plaster. Any recommended paint brand for the wall that vapour impermeable?

 

[fernicarry]

I should also use wood fibre for loft insulation?

For loft insulation you'd be better off with a wool product as it will be easier to fit between joists that may not be regularly spaced. If your ceilings are lath and plaster the back of the ceiling will be quite uneven so it will conform better to that. There are a range of suitable products available ranging from actual sheep's wool based if you are feeling flush through to the standard stuff you can get from B&Q.

Be sure not to block the under-eaves ventilation with insulation.

Any recommended paint brand for the wall that vapour impermeable?

Assume you mean permeable. The topic of which paints are breathable gets quite a lot of air time on this forum with some strongly held opinions being expressed. Rather than kicking off another discussion I would suggest the use of the forum search function.

 

[HCHOC]

For loft insulation you'd be better off with a wool product as it will be easier to fit between joists that may not be regularly spaced. If your ceilings are lath and plaster the back of the ceiling will be quite uneven so it will conform better to that. There are a range of suitable products available ranging from actual sheep's wool based if you are feeling flush through to the standard stuff you can get from B&Q.

Be sure not to block the under-eaves ventilation with insulation.



Assume you mean permeable. The topic of which paints are breathable gets quite a lot of air time on this forum with some strongly held opinions being expressed. Rather than kicking off another discussion I would suggest the use of the forum search function.

Thank you for the advice again!

Yes I meant permeable I'll do some research on the forum about the paint! Thank you again for your help! Really really appreciated!

 

[paulc]

But in terms of bang for buck loft insulation should be your first port of call. Especially if there is none or little there now. You're only looking at a few hundred in materials. IWI is a much bigger task and bear in mind that you will have to remove and reinstate decorative details on the external walls like skirting boards and cornices.

Having completed various thermal upgrades here, loft insulation and double glazed windows have made the biggest difference for me. Killing all those nasty cold draughts around the windows as a result of replacing them probably contributed more than the double glazing. One small change that is often overlooked but can make a noticeable improvement is the loft hatch - A well fitting one with insulation on top, and no more cold draughts getting in.
Having added IWI to a couple of the rooms here, I'm not entirely convinced that it saves much energy. Have temperature/humidity sensors in every room (data is continuously recorded), and comparing the graphs between rooms that have IWI and the ones that don't, I'm hard pushed to see any difference. However, the rooms that do have IWI don't suffer from condensation and the attendant black mould. Also have nice flat walls to boot.

As for loft insulation, I used fibreglass stuffed between the joists and over the top. In places it is around 400mm deep. Have had to replace a couple of the ceilings, and when they came down, took the opportunity to stuff yet more insulation in from below. Not convinced that sheep's wool has any advantage over fibreglass aside from the environmental credentials.