New utility room - freezing

[nrpax]

We had an extension built last year. But the utility room is freezing in winter (gets down to 10 degrees some days), despite having an adequate size radiator (room is 2 x 2.5m). This part of the extension is flat roof and adjoins the main living area and has a door onto the garage. There is a brand new glazed door to the garden but no separate window. As part of the building regs we had to have an extractor fan installed (diameter approx 15cm). I can feel cold air coming through what is effectively a hole in the wall. The garage door is a fire door.

When we mentioned to the builder he said there was nothing to do. I can't understand how a new building that had to meet building regs is so cold? What if we were going to use it as a playroom or similar - it would be uninhabitable.

Can anyone give me any advice?

Thanks

 

[JohnD]

an extractor fan should not let cold air blow in. If yours has no automatic shutters, get a cowl vent.

Did you see the extension being built? Did you see insulation going into the roof, walls and floor?

How many external walls does it have?

Is it a concrete floor?

How is it heated? What size is the radiator? Is it hot all over? Was it tacked onto the pipes of an existing radiator?

 

[Doggit]

What is the construction of the walls, and roof, and was any insulation put under the floor. Was any insulation added to the garage wall when it was done.

And why did you have to have an extractor; is it an extension to the kitchen. Trickle vents in the windows would have been sufficient, but the Airflow Icon fans have a shutter that only opens just after the fan starts, and then closes afterwards.

 

[nrpax]

It's a block a beam floor with concrete

2 column radiator 500x628 1703 BTUs
The pipe work was laid as an extension from the existing radiators. We've got a new combi boiler which is sufficient for the number of radiators.

It has 2 external walls - one very small which has the external door and vent. The other is the length of the room. Then the back wall has the door to the garage. The other side wall adjoins our living room and has the door into the room.

Saw insulation going into ceiling.

Seem to remember the room becoming more narrow because the wall had to be thicker due to it being an external wall - something the architects hadn't factored in.

The separating wall from garage to utility roo. Is breeze block and plaster board.

The builders are a reputable company and was building inspectors checked and signed off at each stage.

There's no window and as it is a utility room with sink a fan had to be Installed. It does have some flaps externally but these seem to just flap about. And there is draft coming through all the time. I was surprised at the size of the hole before the fan was installed.

Sorry I've got very very limited building knowledge!

 

[Doggit]

So what was fitted above the block and beam floor. Fine for the fan as it's a utility room, but take a look at the Airflow fans to cut out the drafts; not cheap, but will solve one problem, but try blocking the fan up first and see if things improve.

You've got two column radiators, but they could be warming the ceiling rather than the room, and were they calculated for the size of the room, or they just fitted in best. If they didn't insulate the garage wall, then you'll get a substantial heat loss through there.

Unfortunately, the building inspectors may have signed it off, but that doesn't mean that it's been specced properly, only that it's been built to the current regs.

Can you post some pictures.

 

[JohnD]

some flaps externally but these seem to just flap about.

you may have one of these
https://www.screwfix.com/search?search=flap+vent
bin it and buy one of these
https://www.screwfix.com/search?search=cowl+vent
the duct size of 100mm is most common but 150mm might be used if the kitchen has no extractor hood.

Post some photos with a ruler, inside and out.

 

[^woody^]

The separating wall from garage to utility roo. Is breeze block and plaster board.

That's a big part of your problem. That wall should be insulated to the same standard as an external wall. It should have 120mm of foil backed insulation board or equivalent on that wall.

That should not have been signed off.

Fit a shutter to that fan.

 

[nrpax]

That's a big part of your problem. That wall should be insulated to the same standard as an external wall. It should have 120mm of foil backed insulation board or equivalent on that wall.

That should not have been signed off.

Fit a shutter to that fan.

It may well have insulation board on that wall and if that's a requirement then I suspect it does - I didn't see all the building work going on. The builders we used are very reputable and have been working in the area for 30 years so I trust them. Thanks!

 

[nrpax]

There's only one radiator but we calculated the BTUs and this one was sufficient

There is screed in top of the block and beam. And then a simple vinyl floor covering (which I assume may add to the cold problem?)

Other pictures as requested

 

[Doggit]

The job looks good, but the radiator looks undersized. If the floors cold, then there won;t have been any insulation underneath it, but vinyl should be warmish. I know you feel the builders are reputable, but somethings going wrong, and they appear to have shrugged off the fact that the rooms cold, and that's a little odd. A 100mm fan should have been sufficient, and it could be that the wind direction is straight on the that wall, so you'd always get a draught through, and fitting a cowl wouldn't achieve much either. If you feel the walls, are all of the even, or is the garage wall colder.

 

[nrpax]

So what was fitted above the block and beam floor. Fine for the fan as it's a utility room, but take a look at the Airflow fans to cut out the drafts; not cheap, but will solve one problem, but try blocking the fan up first and see if things improve.

You've got two column radiators, but they could be warming the ceiling rather than the room, and were they calculated for the size of the room, or they just fitted in best. If they didn't insulate the garage wall, then you'll get a substantial heat loss through there.

Unfortunately, the building inspectors may have signed it off, but that doesn't mean that it's been specced properly, only that it's been built to the current regs.

Can you post some pictures.

We sealed up the vent and it's made a big difference. I still think there are other issues that need to be addressed and we've asked the builder to confirm what was done regarding insulation on all walls, ceiling and floor. But we're going to invest in an airflow vent at least for now. Thanks

 

[jagillham]

Are you getting cold in from the cat flap(s)?

We get breeze in around ours, and I also find the bloomin' cats manage to leave it swinging in the wind on occasion.

 

[nrpax]

I did notice a small draft but it's good a shutting itself! As the flap gets older it definitely gets more air coming in