Ventilating mass concrete house

hooplah

Hi folks,

We moved into an old 1940s mass concrete house last year. After installing new windows and doors we are starting to get patches of mould in some rooms.

I would like to put in some ventilation but am not sure what the best option is. I have thought about putting in 4 inch vents but :

a) it seems like this would be quite difficult work
b) I'm worried we'll have draughts in each room

How would we get around this?

BryanF

Thermal bridges

Lack of ventilation

Lack of heat

-Research Demand control ventilation

- external insulation when installing the Windows would have been best

hooplah

Yeah, I get that external insulation might be the best option for some reasons. We're wary about it though for the following reasons:

- we share external downpipes with neighbours
- after a year in the house the heating is all right to be honest, we don't think we need extra insulation

If I was getting windows again I would but ones with the partial closed / airways open system but there you go.

In the meantime we have to go on from where we are.

I'll take a look at 'demand control' ventilation so. Are you saying that passive ventilation is a non-runner?

Calahonda52

hooplah wrote: »

I'll take a look at 'demand control' ventilation so. Are you saying that passive ventilation is a non-runner?

The terminology is important here, so I am assuming by passive ventilation you mean holes in the walls or vents on the windows as opposed to some mechanically induced ventilation.

Are you happy that walls and floor have damp proof courses?
Do u have extractor fans in bathrooms and a cooker hood.?
What is the ventilation now?
how is house e heated?

sydthebeat

passive stack ventilation

hooplah

Calahonda52 wrote: »

The terminology is important here, so I am assuming by passive ventilation you mean holes in the walls or vents on the windows as opposed to some mechanically induced ventilation.

Yeah I meant holes in the walls.

Are you happy that walls and floor have damp proof courses?

Do u have extractor fans in bathrooms and a cooker hood.?

No. I've contracted someone to do an extractor fan in the bathroom but he hasn't done it yet. It's upstairs and I think he's planning to go into the ceiling and then down through the roof overhang.

We have a cooker hood purchased but actually plan to move our cooker so haven't installed it yet. Would plan for cooker to go into chimney breast and hood to extract to outside wall.

What is the ventilation now?

Opening windows basically. There are some vents underneath the wooden floor on the ground floor but I presume these are just for the floor.

how is house heated?

Gas fired central heating.

Calahonda52

Bathroom solution is typical, lazy, suboptimal and will lead to insulation being disturbed, probably use that flexible hose:eek:

Get a proper, humidity controlled fan, not some piece of crap....

I know its mass concrete but this 2016 and core drills are widely available for hire.
[If you decide to go holes in the wall throughout then might be worth considering getting a professional in to do it]

Do you know if there is any reinforcement in the walls: this can cause issues with teeth falling out of the rented core bits and they are billed as extra, if you rent a core bit, or are liable for the cost of same, check all the teeth very carefully before you use it: there have been cases where a dirty bit is rented and the some teeth are just held in with glue which of course fall out, and you pay..

Is the chimney in use/open?
Don't let then just stick outlet up chimney

hooplah

Calahonda52 wrote: »

Bathroom solution is typical, lazy, suboptimal and will lead to insulation being disturbed, probably use that flexible hose:eek:

Get a proper, humidity controlled fan, not some piece of crap....[/QUOTE]

Ok, I'll look into that. Can you recommend anything?

I know its mass concrete but this 2016 and core drills are widely available for hire.
[If you decide to go holes in the wall throughout then might be worth considering getting a professional in to do it]

yeah, this was what I was thinking of doing. But as I said above I'm worried that I'll just create drafts. How can I place the holes so as to avoid risk of this? i.e. should they be high or low on the walls, high on one side / low on the other, one or two per room etc

Do you know if there is any reinforcement in the walls

I don't know. Is there any smart way to check? Would it be like likely to be around where floors or walls meet or could it be anywhere?

Is the chimney in use/open?
Don't let then just stick outlet up chimney

Chimneys aren't in use but are open - well they're blocked up at the fireplace level if you know what I mean. I wasn't planning to let outlets just go up the chimney.

Calahonda52

http://www.environ.ie/housing/building-standards/tgd-part-f-ventilation/technical-guidance-document-f-ventilation-2009

will PM a link to kit

Am a little "worried" about what will happen with kitchen fan when I see this
Would plan for cooker to go into chimney breast and hood to extract to outside wall.

Are you going to raise the head in the chimney as you say into

hooplah

Am a little "worried" about what will happen with kitchen fan when I see this
Would plan for cooker to go into chimney breast and hood to extract to outside wall.

Are you going to raise the head in the chimney as you say into

I'm not sure what you mean. I thought something like this
the extractor in the chimney, going up a foot or tow and then turned out to the right hand side to vent via the back wall. Again if you have suggestions I'd be delighted to read them.

Calahonda52

Is the chimney one of those old ones you can stand into and look up at the sky!
If not, to achieve what is in the picture shown will require a lot of work which might be problematic given that its against your shared wal and I presume a shared chimney stackl.

Calahonda52

Just kicking around a few ideas here so if they don't make sense to you or the other vastly more knowledgable folk here, please say so.

I know retro fitting of MHVR is not that easy to get done invisibly.
However if you have mass concrete walls with no ventilation or other services holes in them then thats a goo start.

If your doords and windows are airtight then even better

Am assuming the ground floor is concrete and Lets assume the walls are still airtight where the floor joist are embedded in them, assuming this construction.

The attic hatch will be an issue as will any elec conduits that go up into the attic, as will any recessed lights and the open chimneys

So before drilling holes and spending money on room based solutions or some of the more expensive stuff I sent you in the links, it just might be worth giving MHVR a closer look, and then starting with a blower door test.

I think it makes sense to at leat explore it
however it may not suit your budget or your long term plans for staying in the house etc etc etc