pumped loose cellulose roof insulation wet from leak…looking for a repair company

[lizzie]

Hello all 

 

its been a few years. I hope you are all doing well.  Managed to reactivate my account and hoping you clever people can help me once again.

 

I have an MBC house, single storey, flat roof.  During the January storms snow blew into the void between my ‘warm roof’ (the MBC flat roof) and the decorative shaped cold roof that sits on top.

 

The snow melted and water down through the ceiling.  Insurance repairs, freak event.  Top roof has been checked all sound the problem is from the snow melt in the void. Insurance appointed builders will do all the building side its just the insulation part we need help with.

 

My flat roof has no access into it we need to cut out plasterboard to access. There is just the service gap approx 40mm below the VCL and insulation.  I have circa 500cM depth of pumped in loose cellulose insulation that has been wet and Im told will need to be replaced. An area of approx 1sqm but until exposed we cant be sure of extent.

 

I contacted MBC to see if they could help with this.  Their tech manager was helpful told me the VCL would need to be slit, the damaged insulation removed, new pumped in and vcl taped and sealed. He said MBC could give a price for the work etc. I passed his details to the builders and almost 2 months later we are no further forward.  Finally today they had feedback from MBC to say they were not able to help and the tech manager is now on holiday so I cant contact him to find out why they have now said they cant help.

 

I cant get my house repaired until I find someone who can deal with the insulation part of this.

 

Beyond frustrated as you can imagine.  Has anyone got any suggestions of contractors who can do the MBC cellulose type of job who could help with this. As I say its insurance job so costs covered by them not me.

 

Im in the Midlands UK.

 

Many thanks

 

Lizzie

 

[JohnMo]

Contract warmcell, they are a distributor/ installer company. Also look for THERMOFLOC.

[Alan Ambrose]

An interesting problem. ‘Interesting’ for me at least in that we’re about to have insulation blown-in and an answer to what happens if ‘membranes fail and the insulation gets wet’ would be reassuring. I think you need either a proper creative engineer or someone who has fixed this problem before. Sure, call the blown-in importers as they may have exposure to this problem before. You might need their CEO or their top tech person rather than be fobbed off with a lead to their local representative. Alternatively, call a bunch of the local representatives (mostly one-man businesses), describe the problem and see who bites.

 

I’m wondering whether some more creative solutions e.g. just let it dry out or suck out the damp stuff and blow in some dry stuff might work.

 

Do report back to add some info to the hive mind.

[-rick-]

6 minutes ago, Alan Ambrose said:

I’m wondering whether some more creative solutions e.g. just let it dry out or suck out the damp stuff and blow in some dry stuff might work.

 

Thought the sucking it out and then putting in new was a fairly well developed practice. It's done for cavity walls for sure. * I've no particularly experience here just basing this of things I've read hear and elsewhere in the past.

[Alan Ambrose]

Suspect that’s for eps beads rather than wood fibre or cellulose. I hope the same might be true for those two though.

[-rick-]

2 minutes ago, Alan Ambrose said:

Suspect that’s for eps beads rather than wood fibre or cellulose. I hope the same might be true for those two though.

 

No I remember looking at it specifically for mineral wool, not cellulose but I think if you can do it for mineral wool you can do it for cellulose.

[Nickfromwales]

17 hours ago, lizzie said:

Hello all 

 

its been a few years. I hope you are all doing well.  Managed to reactivate my account and hoping you clever people can help me once again.

 

I have an MBC house, single storey, flat roof.  During the January storms snow blew into the void between my ‘warm roof’ (the MBC flat roof) and the decorative shaped cold roof that sits on top.

 

The snow melted and water down through the ceiling.  Insurance repairs, freak event.  Top roof has been checked all sound the problem is from the snow melt in the void. Insurance appointed builders will do all the building side its just the insulation part we need help with.

 

My flat roof has no access into it we need to cut out plasterboard to access. There is just the service gap approx 40mm below the VCL and insulation.  I have circa 500cM depth of pumped in loose cellulose insulation that has been wet and Im told will need to be replaced. An area of approx 1sqm but until exposed we cant be sure of extent.

 

I contacted MBC to see if they could help with this.  Their tech manager was helpful told me the VCL would need to be slit, the damaged insulation removed, new pumped in and vcl taped and sealed. He said MBC could give a price for the work etc. I passed his details to the builders and almost 2 months later we are no further forward.  Finally today they had feedback from MBC to say they were not able to help and the tech manager is now on holiday so I cant contact him to find out why they have now said they cant help.

 

I cant get my house repaired until I find someone who can deal with the insulation part of this.

 

Beyond frustrated as you can imagine.  Has anyone got any suggestions of contractors who can do the MBC cellulose type of job who could help with this. As I say its insurance job so costs covered by them not me.

 

Im in the Midlands UK.

 

Many thanks

 

Lizzie

 

I can PM you Gordon Lewis’s number if you like? He does the majority of MBCs cellulose work.

 

Maybe you can get him to undertake the whole job, as he’s capable of cutting into and reinstating the airtight layers. 

[lizzie]

Nick you are a star that would be great and even more of a bonus if he will undertake the whole job.

 

Thank you!

[Dunc]

MBC are using R.Warville (JW- Insulation.co.uk) for my insulation blow next week.

[Nickfromwales]

20 minutes ago, Dunc said:

MBC are using R.Warville (JW- Insulation.co.uk) for my insulation blow next week.

What area, if you don’t mind me asking. Always looking to add names to the little black book as I’m working all over the place and often need good people who are ‘local’. 

[Dunc]

Scotland - north east highlands. Not sure they're local; think they're travelling from Essex!

[Omnibuswoman]

Hmmm we have had repeated water ingress at the edges of a few of our window frames several hours into a storm, which is likely to have wetted the cellulose within the wall cassette (our wall make up inside to out is propassiv OSB, warm cell, wood fibre board, membrane, cross batten, render board, render). I'm now wondering whether I ought to be exposing and checking these areas before we cover them with plasterboard....?

[SteamyTea]

Some of this blown cellulose (chopped newspaper) has a binder in it (blown in wet).

I would think that would be almost impossible to suck out.

 

But look on the bright side  the heat capacity will go up.  Some say that is a good thing (I disagree).

[Nickfromwales]

21 minutes ago, SteamyTea said:

Some of this blown cellulose (chopped newspaper) has a binder in it (blown in wet).

I would think that would be almost impossible to suck out.

 

But look on the bright side  the heat capacity will go up.  Some say that is a good thing (I disagree).

Goes in bone dry. Comes out with more enthusiasm than you’d ever want.

 

A Henry would remove it in seconds.

 

I’ve had to chop into a few MBC homes retrospectively and it’s a pig of a job, especially ceilings, as the second you cut the AVCL you’re wearing two bin bags worth of it. 
 

Not so bad with walls where it’ll stay put, if you’re very careful. 

[SteamyTea]

8 minutes ago, Nickfromwales said:

Goes in bone dry

Why I typed 

 

32 minutes ago, SteamyTea said:

Some

 

I seem to remember that Jeremy's place was a wet system, he had no problems when he cut a hole for his A/C unit.

[Nickfromwales]

2 minutes ago, SteamyTea said:

Why I typed 

 

 

I seem to remember that Jeremy's place was a wet system, he had no problems when he cut a hole for his A/C unit.

His was MBC, so same stuff from PYC iirc. 

[SteamyTea]

10 minutes ago, Nickfromwales said:

His was MBC, so same stuff from PYC iirc. 

Was a decade ago.

Not saying I am certain, just seem to remember it being mentioned at the time.

Easy way to find out is to pull a fill hole plug out and see.

Sometimes it is quicker just to try things out than constantly speculate.

Edited yesterday at 16:10 by SteamyTea

[Nickfromwales]

19 minutes ago, SteamyTea said:

Was a decade ago.

Not saying I am certain, just seem to remember it being mentioned at the time.

Easy way to find out is to pull a fill hole plug out and see.

Sometimes it is quicker just to try things out than constantly speculate.

No need to   I’m on these projects full time so the last time I had to do this was less than 2 years ago. 
 

AKA “hands on”. On walls it’ll stay put, give or take a few handfuls, but if it’s overhead then it’s going to drop out like confetti. 
 

Removal is simple with an AVCL, as you just make a 2” incision into the membrane and poke Henry’s pipe in there and keep sucking and swinging the hoover pipe about until you’ve got the worst of it and then open up a section.
 

From there you can go to a dustpan and some bin liners.  

[JohnMo]

Seen a few vids with it wet/damp. Suppose to dry out over time

 

https://youtu.be/v_OmMxSbOSw?is=NxKx-3p3KCIq62rJ

[Nickfromwales]

3 minutes ago, JohnMo said:

Seen a few vids with it wet/damp. Suppose to dry out over time

 

https://youtu.be/v_OmMxSbOSw?is=NxKx-3p3KCIq62rJ

Odd. As I was on site just before Xmas and Gordon was pumping in 4 pallets of the stuff. I’d defo say it’s not “wet”, as it puffs out at the point where he injects it, and it’s instantly airborne and floating around. 

[Gone West]

Looks like Jeremy had it blown in. I looked at having it sprayed on damp, but used Icynene in the end.

 

https://web.archive.org/web/20200923194439/http://www.mayfly.eu/2013/11/part-twenty-one-putting-in-the-insulation/

 

 

[SteamyTea]

5 minutes ago, Gone West said:

Looks like Jeremy had it blown in

Right. Memory must be failing, maybe he discussed a wet system to reduce slump, but did not bother in the end.

[jack]

1 hour ago, SteamyTea said:

Right. Memory must be failing, maybe he discussed a wet system to reduce slump, but did not bother in the end.

 

16 hours ago, Nickfromwales said:

Odd. As I was on site just before Xmas and Gordon was pumping in 4 pallets of the stuff. I’d defo say it’s not “wet”, as it puffs out at the point where he injects it, and it’s instantly airborne and floating around. 

 

The stuff you saw was definitely the dry-installed type.

 

Wet cellulose is applied in a completely different way. You start with the wall cavity open then spray in damp cellulose and scrape/compress it flat with the studs before plasterboarding.

 

I've never heard of anyone offering the wet-spray stuff in the UK. My recollection is that Jeremy discussed it in response to expression of concern about post-installation slump of the dry stuff. 

 

Personally, I do have some concerns about how perfectly dry-installed cellulose fills cavities, especially for flat roofs, under windows and the like, and tall walls where there's a lot of weight compressing the cellulose at the bottom. I'm sure there's an element of installer skill, too.

 

On 13/03/2026 at 18:37, lizzie said:

My flat roof has no access into it we need to cut out plasterboard to access. There is just the service gap approx 40mm below the VCL and insulation.  I have circa 500cM depth of pumped in loose cellulose insulation that has been wet and Im told will need to be replaced. An area of approx 1sqm but until exposed we cant be sure of extent.

 

Water can travel a long way through cellulose. I guess the thing you have in your favour is that you only had a fixed amount of ingress based on the one-off snow event, so hopefully it won't have gone too far. In our case, we think the leak was there for months, which allowed it to saturate a lot of cellulose. We had two leaks - this was the worst of them:

 

 

On 14/03/2026 at 10:23, Alan Ambrose said:

I’m wondering whether some more creative solutions e.g. just let it dry out or suck out the damp stuff and blow in some dry stuff might work.

 

With an area as (hopefully) small as this, @lizzie might get away with making a smallish opening, pulling out the wet stuff, then manually pushing fresh stuff back in manually. To be honest, with such a small amount I'd be tempted to pull it out, dry it properly, and re-use it. Except for the re-use, that's what I did when we had another leak (scaffolders punctured an aluminium trim on the flat roof above the garage and didn't tell us about it, so first we realised was when we spotted the leak). Not the most pleasant job in the world, and you will make a mess, but it worked out okay. The cellulose sort-of stays put when you compress it, so you just keep stuffing it up until the space is full.

 

For a small patch, allowing it to dry out is a possibility. You could consider piping dry air from a dehumidifier into the service void for a couple of weeks.

 

Personally, I'd be happier if I knew it was all properly dried out, including any wooden elements in contact with it, so I'm not sure I'd risk it.