Advice needed - How this entrance can be thermally insulated?

[fleyh]

Hello everybody,

Our house was built in 1970s with cavity walls and aluminium door.
We have recently replaced old aluminium door with a PVC one (installation day naturally fell on the coldest day of this year so far).
Part of the reason to replace the door was an assumption that it will improve thermal performance and make our entrance hall warmer.

In actual fact - entrance hall now feels considerably colder, so much so, that I had to hang some heavy curtains trying to keep some warmth inside.

I am a bit puzzled as to where to go from here and looking for advice:
A. Is there something wrong with the new door (I can not see any obvious gaps) i.e. why did it get colder than with the old aluminium door
B. What is the best way to thermally insulate areas 3), 5), 6), 7) leaving some space for finishing wall/floor covering


For context: the original idea was simple - once the new PVC door is installed - to raise areas "3)", "4" and "5)" (see photo) to the level of the main floor with some cement/screed and then lay some floor covering on top.

Space available:
3) is 70mm below main floor level
5) is 30mm below main floor level - it used to be where stairs ended, but last large step had to be reduced in depth due to new door position and hinges on the left
6) and 7) can not add more than 15mm without encroaching too much on the door frame

Areas 8) and 9) always have considerable amount of moisture/condensation in the morning.


Does anyone have any suggestions on how to fix this mess? It sounded so simple in theory...
I did discuss the temperature drop with our door installer - he was unable to suggest anything.

 

[D_W]

Other than sheathing with rigid insulation and covering that, i've got no great ideas.

In the old days, if that area was really cold but you weren't going back and forth at night, you might devise some kind of curtain to close it off from the rest of the house, but good luck with making that look *not* garish, intrusive or bulky.

I know what my father in law would do, which isn't a suggestion - he'd cut a piece of rigid insulation to fit the door and put it there each evening and take it back out in the morning.

 

[rogxwhit]

I must say that I'm astounded that this wasn't thought through beforehand. It would seem a lot to spend on a wing and a prayer. However - there's a lot of cold bridging going on! About 'encroaching', why not? The circumstances decree that you must encroach as much as possible! I think I'd go for insulated (foam backed) plasterboard fixed tight to the brickwork (no battens!) at both sides. And insulate the floor level as you raise it the full 70mm.

 

[fleyh]

Other than sheathing with rigid insulation and covering that

Thank you. @D_W.
Do you have a suggestion how to seal the gap between the insulation board and the door frame on the walls and on the floor area?

I must say that I'm astounded that this wasn't thought through beforehand

Well, it is a bit too late now in my case. I am a woodworker, not a builder. Remedial work after door removal/install was discussed with the door installer beforehand. He said nothing about the need to insulate or suggested that thermals can get worse.

I think I'd go for insulated (foam backed) plasterboard fixed tight to the brickwork (no battens!) at both sides

Thank you @rogxwhit.
I am a bit hesitant about using insulated plasterboard here due to the amount of moisture/condensation visible around the door frame at the moment. I could not find "insulated moisture resistant" plasterboard.
Will something like "Kingspan insulation board" + separate "moisture resistant plasterboard" be suitable here? And what would be a good way to fix both to the wall or to each other?

 

[Jacob]

Areas 8,9 should have condensation collecting channel to drain to outside. No help with the cold though!
Better quality aluminium doors would have insulation within. Maybe you've swapped for something inferior?

 

[Spectric]

When we did something similar we kept the original door but fitted our new door to the outside like yourself, now we can enter / exit without letting the heat out of the house and have an area to store coats & shoes.

 

[fleyh]

Areas 8,9 should have condensation collecting channel to drain to outside. No help with the cold though!

Below is the outside view of the door.
Do you mean the hole where arrow points?
We do have 1 on each side of the door (left/right) but I am not sure how they may help moisture from inside to drain outside since that would imply there is a direct path for cold air to travel to the inside.

 

[fleyh]

When we did something similar we kept the original door but fitted our new door to the outside like yourself, now we can enter / exit without letting the heat out of the house and have an area to store coats & shoes.

Good advice. Thank you. One of the main reasons to install the new door was to get rid of the hideous original aluminium one. The other reason was to make entrance hall a bit longer. With the original door position - carpeted staircase to the first floor was bearing against the front door, i.e. muddy boots on the carpet.
Although - knowing what the removal of the old door would lead to - we would probably think twice about removing it.

What I do not understand is why the original (theoretically inferior) door was better than a brand new (supposedly "better") PVC door at keeping warm air inside. That's not to say that aluminium door kept a lot of warmth, but certainly did better job than the new one.

 

[Jacob]

Below is the outside view of the door.
Do you mean the hole where arrow points?

Probably. Have a look on the inside and see how water could drain off. It might have got blocked in the frost.

We do have 1 on each side of the door (left/right) but I am not sure how they may help moisture from inside to drain outside since that would imply there is a direct path for cold air to travel to the inside.

Actually an indirect path talking several turns, which reduces air flow, but not to zero.

 

[Doug71]

As said you have a lot of cold bridging going on there, the piece of hallway you have gained was designed to be outdoors but it's now indoors, for example the concrete slab under the quarry tiles will not be insulated so will be a real cold spot.

The new door isn't the problem, the cold is coming in through the area of walls and floor that were originally outside, insulation should help a lot. I guess the old door was also protected from the weather as it was set back but the new one is more exposed.

The holes will just be to vent/drain the DG units.

 

[D_W]

Thank you. @D_W.
Do you have a suggestion how to seal the gap between the insulation board and the door frame on the walls and on the floor area?

I would use something like rockwool or kawool and cover it with trim if it can be done without things looking garish. It's not perfect, but it's better, and sometimes better and easily reversed seems a lot better than magic adhesives and fillers.

 

[Sachakins]

It could just be that area now inside the house is holding a thermal mass of coldness.
It will require a bit of time for the internal heat to add warmer thermal mass to this now internal structure.
Also as it was initially external, more moisture would be present, now its internal It needs to release this.
I would leave insulating those walls till moisture level and the thermally cold areas have warmed up to the natural Internal wall temps of the nearby internal walls.

 

[HOJ]

You've basically moved the new door outside the "thermal envelope" are the side walls solid 9" or cavity insulated? the combination of all those cold surfaces is going to cause issues until it warms up and dries out and then you can insulate, as @rogxwhit said max out on the insulated PB on the walls, plenty of options as to how you fix it using propriety glues/adhesives and a few mechanical fixing as well (screws). PUR on the floor with a vapour barrier under and over then floating floor on top perhaps, not ideal though.

You can't put a screed floor down its not deep enough to do, with any insulation, with hindsight you should have dug it up and run 2 or 3 course of bricks across the opening to land the door on then you could have possibly got 100m of insulation and a shallow screed on the floor.

I typed this offline, but now see that @Doug71 & @Sachakins have said pretty much the same.

 

[Molynoox]

An extreme option could be to add another brick skin to outside wall and insulate in between.
Other than that I would say just add the max insulation to the inside that you can, PIR being the most space efficient and hence best for your application.
Good idea to let all the moisture disappear first though

 

[D_W]

I would use something like rockwool or kawool and cover it with trim if it can be done without things looking garish. It's not perfect, but it's better, and sometimes better and easily reversed seems a lot better than magic adhesives and fillers.

Speaking also as someone who knows absolutely nothing about building codes, if I were concerned about condensation between the brick and the insulation - I'd paint the back side of the rigid insulation with anti-mold primer.

This may sound like a yokel move (as my dad would say), but being that we're woodworkers and not "house people", I'd rely on being able to untack the trim to look at the kawool filler and maybe make some provision to be able to eyeball the brick after a couple of years to see what's happening. the brick can always be bleached later, I guess.

the advent of cheap fiber scopes with LED lights on the camera tip makes it not that difficult to make some kind of provision for this.

 

[fleyh]

An extreme option could be to add another brick skin to outside wall and insulate in between.
Yes, building something outside is a good idea. We did consider adding a a small extension/porch at some point, but wanted to delay that by a couple of years.

Other than that I would say just add the max insulation to the inside that you can, PIR being the most space efficient and hence best for your application.

Understood. thank you.

Good idea to let all the moisture disappear first though

Thank you everyone for explaining about the need to wait for moisture from the (now internal) wall to evaporate. Looks like we've chosen the worst time of year to change the door.

 

[fleyh]

if I were concerned about condensation between the brick and the insulation - I'd paint the back side of the rigid insulation with anti-mold primer.

Sounds like a good idea. I had not thought about that. Thank you @D_W

 

[D_W]

Sounds like a good idea. I had not thought about that. Thank you @D_W

You could also add pictures of hillary clinton and donald trump in swimsuits to the back of the rigid insulation. Nothing living would ever try to locate across from them, but even the bricks might flee.

 

[fleyh]

You can't put a screed floor down its not deep enough to do, with any insulation,

I was thinking - since we have 70mm in area "3)" (from the tiles to the internal floor level) - I could do something like this

1. put damp proof membrane on the tiles (like if I was preparing this for shower tray)
2. then 50mm insulation board on top of the membrane
3. then 10mm (or so) screed to level the whole thing and then some floor covering on top.

Do you think this is a bad idea @HOJ ?

 

[Sachakins]

One solution you could try to speed up the thermal mass and reduce the moisture quickly would be the use of a dehumidifier temporarily in the new reclaimed space.
This would draw out the moisture and collect it so it doesn't remain in the house, just empty it regularly. It will also add localised warmth in the area to impart warm thermal mass into the cold brick.

Maybe hire a decent one for a week.