Cavity wall insulation - cannot find the insulating material

bjdodo

Hi

I live in a 3 bed mid-terrace house in Galway. In 2010 we have had cavity insulation done, the technology used is called platinum bonded bead. We have a very cold bedroom in the house. Today I have drilled the external wall from the room into the cavity and I do not feel that anything is there in the cavity other than cold air, the drill bit moves absolutely freely, I can touch the external wall (on the other side of the cavity) 10 times out of 10 just by pushing the drillbit into the hole, feel no obstacles, no particles etc. However now the cold air is coming straight into the room, if I wet my hand and put it in front of the hole I can feel the breeze. For curiosity I have drilled the wall between us and the neighbor as well, found a cavity there as well, feel the breeze the same way. My questions:

1. Is there a better way to check that there is actually insulation material in the cavity?
2. Would it make sense to redo the cavity wall insulation (this time with a different company)?
3. Is it possible/advisable to get cavity wall insulation between us and the neighbor? I guess if the breeze is coming out then cold air is moving in there which of course cools the room.

Thank you for all replies!

Joe

MicktheMan

bjdodo wrote: »

1. Is there a better way to check that there is actually insulation material in the cavity?
2. Would it make sense to redo the cavity wall insulation (this time with a different company)?
3. Is it possible/advisable to get cavity wall insulation between us and the neighbor? I guess if the breeze is coming out then cold air is moving in there which of course cools the room.

1. Yes - thermal imaging is a non destructive method in the right conditions followed by a cavity inspection using a borescope for certainty
2. Depends on the result of 1 above but if the first job was not done properly I would be chasing the original insulation company first to correct the situation. If it was SEAI grant aided then I would also contact SEAI.
3. Are you sure the party wall is a cavity wall? If it is then yes this should be insulated also.

Btw, if your house suffers from draughts, pumping the cavity (even if done properly) will have little if any effect.

bjdodo

Thank you for your answer.

What do you recommend against the draught? I guess this means that the cavity has an opening to the outside world somewhere. Is there a strategy to find this problem?

For doing thermal imaging, what should I be looking for in advertiser to find a professional who can do this? Do builders usually have this equipment?

MicktheMan

bjdodo wrote: »

1. Is there a strategy to find this problem?

2. For doing thermal imaging, what should I be looking for in advertiser to find a professional who can do this? Do builders usually have this equipment?

1. Yes, a house depressurisation test aka blower door test

2. Google "heat loss survey" or "thermal imaging". In my experience, builders don't like thermal imaging cameras:D

cerastes

Im not convinced by the whole cavity insulation, how can they guarantee they could fill the cavities completely? you might have some filled and others, maybe due to being blocked by mortar not being filled, I personally prefer the idea of external insulation, but I would want to see some calculations on dew point at various temperatures and the performance of the insulation.

I looked into the idea of external insulation out of curiosity and the cost was fairly high, plus it isn't always practical to get external insulation done.

Any ideas where Id find something specific for calculating heat loss and dew point that I could then play around with? I dont have the money to get anything done now anyway. I do think its only something worth doing if you know what the result will be and if its done right. Getting someone that is able and willing to do a job properly is a big part of it as far as I'm concerned, Just getting insulation or any work done that happens to have insulation thrown in and no idea how it will perform is nearly not worth it as far as Im concerned.

MicktheMan

cerastes wrote: »

I personally prefer the idea of external insulation, but I would want to see some calculations on dew point at various temperatures and the performance of the insulation.

Why would dew point be an issue with ewi?

cerastes

MicktheMan wrote: »

Why would dew point be an issue with ewi?

Sorry, I dont know what you mean, while Ive covered some aspects of heat loss, really I dont have practical experience of applying it to a domestic/building scenario, I'm just posting if I see something I think is relevant so that when (if) the time comes for me to do anything, Im as well informed as possible about the right things to ask/determine if the person I am dealing with actually knows what they are talking about.

My specific concern is insulating some aspect of my property and instead of saving from reducing heat loss, actually creating a problem such as moisture somewhere between the layers that will (could) deteriorate the structure somehow, maybe cause health problems??, negate the purpose of spending money to improve the performance of the building, and likely actually costing money to rectify.

so ewi?? I dont know what that means, what is it? external wall insulation??
I make no claims to know more than I actually do.
Concerned about what Ive heard people (employed to carry out work) say regarding improvements regarding insulation, that some really aren't aware of the potential problems.

MicktheMan

ewi = external wall insulation:)

bjdodo

> Yes, a house depressurisation test aka blower door test
What I found is that during this process they increase pressure within the house via the door and then watch where some smoke escapes. Can they do the same with the cavity itself? Meaning they drill a hole in the house wall, increase pressure within the cavity and and then see where smoke leaves the cavity?

Thank you again.

MicktheMan

cerastes wrote: »

My specific concern is insulating some aspect of my property and instead of saving from reducing heat loss, actually creating a problem such as moisture somewhere between the layers that will (could) deteriorate the structure somehow, maybe cause health problems??, negate the purpose of spending money to improve the performance of the building, and likely actually costing money to rectify.

Your concerns are not unfounded.

cerastes

MicktheMan wrote: »

ewi = external wall insulation:)

Fair enough, I wasnt sure what you were saying when I first saw it, then twigged it and added it to my post with q mark, I actually posted in another thread too.
At the moment, Im weighing the possibilities of what can be done, as basically there is no money to do anything. Mostly its come up as Ive come across a few people that are getting attic conversions done, and it all seems to be based on a builder coming in and just ptting in an extra room and put some insulation in but no calculation, so no idea of heat loss performance or if condensation will develop or not.

For the same reason I weighed the options with external insulation, but made an enquiry as to the price, and was shocked, plus no suggestion of any calculation done or how it would perform, plus some problems even I could forsee, which didnt seem to be catered for.
ie insulation ends at property where it joins a neighbour? how does this affect insulation and condensation at that point,

Cavity wall insulation, concerns me as I dont see how it can be confirmed that a cavity wall could be filled completely, plus, how does any possible moisture in the block escape?

Internal, well concerned about condensation developing inside the structure somewhere between the external surface of the insulation and the outside.

cerastes

MicktheMan wrote: »

Your concerns are not unfounded.

I nearly feel it would be better off if I didnt know there are potential problems.
Im at the view, its better to do nothing option, than spend money for no improvement or worse, deterioration.

MicktheMan

bjdodo wrote: »

> Yes, a house depressurisation test aka blower door test
What I found is that during this process they increase pressure within the house via the door and then watch where some smoke escapes. Can they do the same with the cavity itself? Meaning they drill a hole in the house wall, increase pressure within the cavity and and then see where smoke leaves the cavity?

Thank you again.

While I have pressurised the cavity with smoke in the past (in very specific cases), in general, the cavity is treated as outside the airtight envelope and is never sealed (nor would you want it sealed)

MicktheMan

cerastes wrote: »

I nearly feel it would be better off if I didnt know there are potential problems.
Im at the view, its better to do nothing option, than spend money for no improvement or worse, deterioration.

Imo, the do nothing option is wrong.
Spend the money on good investigation & specification first and then go get it done. Getting the supplier to specify is not a good idea generally especially when the insulation salesman has his sales target to meet.

cerastes

MicktheMan wrote: »

Imo, the do nothing option is wrong.
Spend the money on good investigation & specification first and then go get it done. Getting the supplier to specify is not a good idea generally especially when the insulation salesman has his sales target to meet.

I feel like Im hijacking the thread at this point, so as there are no immediate plans I'm going to leave it at this, but what you say is something I agree with,i.e. the person doing the job should be following the planned instructions of someone else, not installing based on opinion or previous experience.
Ive done a little on heat loss calculations in the past and I dont think some people realise whats involved, I dont try to say I fully understand it.

So, Im uncertain who to look to, to specify any changes, while there is nothing there financially to get anything done now, and its likely any changes in the future would be staged, I still like to make plans to make better use of internal spaces and improve insulation, so I know whoever might be doing knows what they are talking about and what the concerns are.