How to add insulation to this wall?

[drabina]

I have a mudroom which in a winter time is very cold. There are couple of issues that contribute to this. Underneath the mudroom is a crawl space which has just joists and fiberglass between them. There is one vent that is currently closed with a piece of green insulation (shown on photos) as I have tried to prevent cold air from accessing the crawl space from the outside (the sliding vent cover is no sealing enough when closed). Another issue is that the walls are thin and they just feel cold to the touch. There is fiberglass between studs underneath sheetrock. Without ripping walls on the inside to replace the fiberglass with better insulation, can you guys think of any way to insulate the mudroom from the outside?

 

[Snoonyb]

Blocking the vent will accomplish little in the way of preventing heat loss.

What is the source of the comfort heating, for this space?

 

[drabina]

I have a 4ft baseboard heat in the mudroom. There is 1 window and 1 door. Open space between mudroom and rest of the house. There is a closet on the wall where door is and the opposite wall has a full wall built-in so the open space is not that big. There are some drafts by the light switches that I am planning to insulate with fireproof foam. Other than that the floor and walls are cold to the touch. Unfortunately, the crawl space is not really accessible even to crawl into (too small).

 

[Snoonyb]

Thanks.

It sounds more like the heating appliance is not doing the job. Is it on all the time?

 

[drabina]

The baseboard heat is part of the first floor heating system so it is not separate. I cannot run it all the time. Next room is 6-8 times the size with only 6ft baseboard and heat works fine there. I think the problem is with weak insulation of the walls and the crawl space underneath. Plus some drafts that I am planning to address. The walls are cold to the touch. Colder than other rooms. Floor is ceramic tiles that are also cold.

Anything I could add to the outside? I do not mind removing the siding as it is a lot less messy job than removing sheetrock on the inside.

 

[Snoonyb]

I would first operate the heating consistently and leave the door open to the space, because a balanced circulation maintains a level temperature.

 

[bud16415]

I have a similar mud room off the kitchen that was a small porch open to the sides with just a roof and crawl space. The last owner closed it in and converted it to a warm area by removing the door and letting the kitchen heat it.


Great idea in the summer not so good when it hits –30f.


Same problem you have cold walls and very cold floor. It had a large opening for circulation and I closed that up and it helped a little. It needs someone to get under there and spray foam it. barely enough room to get in there.


Holly wants to just hang a heavy curtain in the entry for the winter and block it off. She doesn’t mind the cold but hates wasting heat. We might try that this winter for the few coldest months.


From the outside you could add 4” foam and then siding over that, but it will mess up the lines of the house and roof, windows and doors. Adding more heat works but that just masks the issue. You could hand dig room to get under there and work on it from below. 40 years ago I would have been all into doing that. Today no way.


As much as it seems more work from the inside it most likely would be the easiest way to go. Take the walls down and build them thicker better insulation. Rip the floors up and do the same.


I have been thru all the ideas on ours and will most likely live with it and maybe block it off for winter months with a curtain of some sorts that we could take up and down like when company comes at Christmas.

 

[drabina]

From the outside you could add 4” foam and then siding over that, but it will mess up the lines of the house and roof, windows and doors.

I have looked at the wall and the most I could add is 1-1.5" of foam. 2" would be flush with the edge of the roof and 4" would require extending roof line.

I will try to seal all the air leaks and see if I can insulate the crawl space a bit more though that may be tough looking at the small opening. I only have a small vent window to work with.

 

[vinny186]

You could cut small holes (save the cutouts) in the drywall to blow in insulation, then patch the holes.
Regarding the floor, like was previously mentioned, tear it up and insulate between the joists or just remove the tiles and install electric heating then retile. The easiest option would be to lay down a grid of 1x2s over the existing floor, insulate and retile however you'll have to deal with a little step when entering/exiting the room.

 

[nealtw]

Heat goes up so the floor will always be cold, closing the vent will only cause other problems it is there for a reason.
You could add foam to the outside under the siding but the design of the roof would make that problematic to make it water tight. You haven't got a vapour barrier or not done properly if you are getting drafts or your house needs more air to replace what fans and people are using.
To add more to the walls would be to remove the drywall, add to the thickness of the walls .
What about the attic?
If this was an addition the heat would have been taken from a connection in the kitchen, so some re wiring could be done either at the Tstat or the kitchen heater so the power goes directly to the mud room and a Tstat could be added to the baseboard there. Or you could re do the tile floor with in floor heat.