Should there be a void between 2 houses

bambam26

HI,
Looking for some advise please. I have an issue with a draughts in my house that I cant find the source of ( also have mice getting into somewhere )

My house is a terrace house but is stepped back on front and back from my neighbors house with my ESB, Gas and Phone boxes on my neighbors wall. While looking for entry points for both wind and rodents I was able to remove the Phone box I have noticed that between my wall and the neighbors wall there is a large gap , could be about 200mm or more running the length of the house with some aero board stuck here and there definably not tight all the way along, and there is a noticeable wind traveling through.

Stupidly I seal back on the phone box before I took any picture.

Is this normal to have a cavity between 2 housed and if so I take it that it is near impossible to fill it to stop anything getting in ?

Thanks

sydthebeat

bambam26 wrote: »

HI,
Looking for some advise please. I have an issue with a draughts in my house that I cant find the source of ( also have mice getting into somewhere )

My house is a terrace house but is stepped back on front and back from my neighbors house with my ESB, Gas and Phone boxes on my neighbors wall. While looking for entry points for both wind and rodents I was able to remove the Phone box I have noticed that between my wall and the neighbors wall there is a large gap , could be about 200mm or more running the length of the house with some aero board stuck here and there definably not tight all the way along, and there is a noticeable wind traveling through.

Stupidly I seal back on the phone box before I took any picture.

Is this normal to have a cavity between 2 housed and if so I take it that it is near impossible to fill it to stop anything getting in ?

Thanks

if this outcrop wall is the side wall of your neightbours house, then yes its expected to have a cavity (if its a cavity wall build)

where are the draughts getting in to your house? and can you not solve this problem internally in your own home?

bambam26

sydthebeat wrote: »

if this outcrop wall is the side wall of your neightbours house, then yes its expected to have a cavity (if its a cavity wall build)

where are the draughts getting in to your house? and can you not solve this problem internally in your own home?

Hi,
No idea where the draught is coming in from, but I can feel it behind skirting boards and plugs and from fuse box. Window are new triple glaze and attic is spray foam insulation, draught was there before both where done. I thought there may be a hole somewhere between mine and the neighbours house letting air and the mice In , I can’t think of or see anywhere else that would be allowed either to get into the house

sydthebeat

is your house timber frame or cavity wall?

bambam26

sydthebeat wrote: »

is your house timber frame or cavity wall?

Cavity wall which had beads pumped into it although I don’t think it was done well.

sydthebeat

feeling draughts around sockets is weird....as youd expect a thick sand coat in the walls before a decent gypsum plaster finish.

i wonder is your house in a housing development, and if so, did they plasterboard the walls?

bambam26

sydthebeat wrote: »

feeling draughts around sockets is weird....as youd expect a thick sand coat in the walls before a decent gypsum plaster finish.

i wonder is your house in a housing development, and if so, did they plasterboard the walls?

Yes it’s a housing development, I think 15 years old. There is plasterboard but not into the block, there is a gap between plasterboard ,Non insulated and block. If u knock on the wall it Sounds hollow at front an back of house. Side walls are solid

Yellow_Fern

bambam26 wrote: »

Yes it’s a housing development, I think 15 years old. There is plasterboard but not into the block, there is a gap between plasterboard ,Non insulated and block. If u knock on the wall it Sounds hollow at front an back of house. Side walls are solid

Can you peer behind the plasterboard when you are in the attic?

bambam26

Yellow_Fern wrote: »

Can you peer behind the plasterboard when you are in the attic?

no I don’t thinks so, attic is spray foam insulation which looks to go right down to the block

Yellow_Fern

bambam26 wrote: »

no I don’t thinks so, attic is spray foam insulation which looks to go right down to the block

I guess the ceiling plasterboard blocks off the cavity behind the plasterboard, which is a good is a good sign IMO.

sydthebeat

bambam26 wrote: »

Yes it’s a housing development, I think 15 years old. There is plasterboard but not into the block, there is a gap between plasterboard ,Non insulated and block. If u knock on the wall it Sounds hollow at front an back of house. Side walls are solid

sounds like you have unrendered dry lined blockwork at the front and back... disaster for air tightness......

BryanF

Yellow_Fern wrote: »

I guess the ceiling plasterboard blocks off the cavity behind the plasterboard, which is a good is a good sign IMO.

is it?

Yellow_Fern

sydthebeat wrote: »

sounds like you have unrendered dry lined blockwork at the front and back... disaster for air tightness......

Maybe the OP could assess this in the power outlet openings?
Is this fault common in Ireland?

BryanF wrote: »

is it?

One less draught route.

bambam26

Yellow_Fern wrote: »

Maybe the OP could assess this in the power outlet openings?
Is this fault common in Ireland?


One less draught route.

Yes if I take off the socket I can see the wall behind the box is just bare,

Yellow_Fern

bambam26 wrote: »

Yes if I take off the socket I can see the wall behind the box is just bare,

As sydthebeat mentioned, removing the drywall and rendering, although disruptive may make a big difference. A blow test might provide additional precision in identifying all the issues.

bambam26

Yellow_Fern wrote: »

As sydthebeat mentioned, removing the drywall and rendering, although disruptive may make a big difference. A blow test might provide additional precision in identifying all the issues.

Removing drywall may not be an option, we have custom made shutters that fit around the windows framed inside the rooms so the old plasterboard would be difficult to remove and replace without disturbing the shutters.

I seen some things online about injecting spray foam into the space behind drywall. Maybe that could be an option ?

Calahonda52

what wall vents do you have?
if you have some then take off the inner cover and post a picture here
My thinking is that wind is getting in behind the PB from the wall vents?

bambam26

Calahonda52 wrote: »

what wall vents do you have?
if you have some then take off the inner cover and post a picture here
My thinking is that wind is getting in behind the PB from the wall vents?

I sealed all gaps between vents and plasterboard with expanding foam, really is baffling where the entry point is

MicktheMan

bambam26 wrote: »

I sealed all gaps between vents and plasterboard with expanding foam, really is baffling where the entry point is

here:

bambam26 wrote: »

Yes if I take off the socket I can see the wall behind the box is just bare,

bambam26

MicktheMan wrote: »

here:

There is no gaps externally around window, sills or doors all look sound and sealed. External wall are rendered and painted at the front and pebble dash at the rear. Cavity front and back are pumped with beads and as we get mice in the attic ( so far only ever in the attic) every year since we moved in there must be a hole somewhere and the only place I can think of is the cavity between mine and next doors house. I am at a loss as to A: how to find it and B: how to seal it.

MicktheMan

Stop looking outside!

A bare block wall is porous to air. Your inner leaf block wall is bare block. Air is passing through your inner leaf from the cavity. You don't (i.e. can't) stop air from entering the cavity. It being pumped with bonded bead is immaterial.
You always tackle air leakage from inside.
So, short of removing all internal pb and applying an air tight plaster finish to the bare block walls you left with dealing every junction (floor, ope, ceiling), hairline crack, electrical socket and penetration of the wall with a combination of air tight foams, paint, tape and compressed earthwool depending.
Not easily done, but will make a huge difference if done right.

bambam26

MicktheMan wrote: »

Stop looking outside!

A bare block wall is porous to air. Your inner leaf block wall is bare block. Air is passing through your inner leaf from the cavity. You don't (i.e. can't) stop air from entering the cavity. It being pumped with bonded bead is immaterial.
You always tackle air leakage from inside.
So, short of removing all internal pb and applying an air tight plaster finish to the bare block walls you left with dealing every junction (floor, ope, ceiling), hairline crack, electrical socket and penetration of the wall with a combination of air tight foams, paint, tape and compressed earthwool depending.
Not easily done, but will make a huge difference if done right.

Thanks for the reply I will have to look at doing that I think,

I have a bathroom that completely sits out over my front door and walls external on 3 sides, flat roof, the ceiling of the porch ( this is open on 3 sides also ) underneath is just really cheap wooden cladding and by the looks of it all that is between that and the bathroom floor is some badly fitted fiberglass insulation. the bathroom is due to be renovated in a few weeks so will take the opportunity to strip back to block and insulate properly and lift the floor and insulate there correctly as well, may not fix the issue but it would be a start.

Would you know if where the floor of the overhang meets the floor of the house would be on continuous void so if not sealed or insulated correctly effectively if air was coming in from the outside via the porch celing/bathroom floor it would just blow into the rest of the house under the floorboards and circulate around behind the walls ?

Yellow_Fern

bambam26 wrote: »

Thanks for the reply I will have to look at doing that I think,

I have a bathroom that completely sits out over my front door and walls external on 3 sides, flat roof, the ceiling of the porch ( this is open on 3 sides also ) underneath is just really cheap wooden cladding and by the looks of it all that is between that and the bathroom floor is some badly fitted fiberglass insulation. the bathroom is due to be renovated in a few weeks so will take the opportunity to strip back to block and insulate properly and lift the floor and insulate there correctly as well, may not fix the issue but it would be a start.

Would you know if where the floor of the overhang meets the floor of the house would be on continuous void so if not sealed or insulated correctly effectively if air was coming in from the outside via the porch celing/bathroom floor it would just blow into the rest of the house under the floorboards and circulate around behind the walls ?

I think this changes things. Its very hard to know how it works from the forum, and unlike blocks, overzealous sealing might lead to rot. hard to say.

Ignoring that overhanging wood frame part I think sealing the block with cement would do a lot of good but it possible that that the wood frame part if a worse problem.

MicktheMan

bambam26 wrote: »

Would you know if where the floor of the overhang meets the floor of the house would be on continuous void so if not sealed or insulated correctly effectively if air was coming in from the outside via the porch celing/bathroom floor it would just blow into the rest of the house under the floorboards and circulate around behind the walls ?

More than likely, yes.
Your best bet is to have the house tested for air tightness and then you'll know for sure what's going on and what to do about it.

Yellow_Fern

BTW although disruptive, these measures can have other benefits. Like sound proofing.

If you couple a wet plastered blockwork with something like genie clips when you put back the metal studs holding the plasterboard you can have a big reduction in noise pollution. Plus it gives the opportunity to add cabling for ethernet etc too.