Sealing in an old Sun room

[robertlennie]

I went to install a new receptacle in a 2nd storey house. When i removed the drywall I found black mold. Like a good DIY'er I removed all the affected drywall (the entire room!), as well as the underlying panelling (used instead of sheathing I guess?) and under that rotted insulation, clothing etc. I have cleaned it all up - and I am ready to rebuild.

So what I found that this room must have been an old sun room - it has old windows from waist high to the ceiling. The mold is a result of numerous gaps and holes in the exterior wall - which is just plywood attached to the outside of the house, and siding on top of that. The roof is flat and directly on top on the room - ie no roof joists or gable. In some of the rotted wood - I can see shingles!

My question is - without tearing down the entire room and rebuilding it - like it probbaly should be - what is my best course of action? I thought I should fill in the holes with foam insulation, then batt insulation over the broken windows and any gaps, then a vapor barrier, then some 3/4" plywood sheathing, and then drywall on top of that.

[scuba_dave]

Without fixing the water problem you are just going to be having the same mold growing again. You need to seal the outside 1st, then work on the inside
You said you can see shingles thru rotted wood - roof shingles? If that is the case & the roof is rotted you will need to rip the roof off & re-roof
if no roof joists then as snow load builds that roof will flex allowing water to enter. Redo the roof, put in joists. I'd get rid of the flat roof & put a window or two in if you will heat the room. Get rid of the single pain windows, they are an immense heat loss
Is the floor insulated? Over another room?

[robertlennie]

I agree - I want to fix the outside problem - and I will - when the weather permits (we just got another 40cm of snow) The picture you are looking at is what used to be under old panelling and drywall. So I want to insulate the room, and cover the windows back up.

[Bumblerazz]

Trying to do anything now will be a complete waste of your time and money, since anything you put in now will require replacement in spring.

Unless you need that room, I would close the door, seal with tape and wait until spring. Then rip the roof off and start there (as Dave says, proper joists with a slope, even if you lose some headspace at the wall), then work your way down, replacing window frames with proper studs, insulation and vapour barrier. Rewire as necessary (good opportunity with the walls open!). Unless you're planning to unload this house in the near future, leaving it that way will only cause you grief, and sooner than later.

Dave's mention of some proper windows is a good idea, especially if the room gets a lot of sunlight (I assume if it was once a sunroom).

If you're really stuck, what you suggested will tide you over until spring, though you may have to shovel the roof on a regular basis to avoid leaks or collapse. The 3/4" plywood is unnecessary. You might put it on the outside with the siding on top, and definitely on your roof! :)

By the way, does the mould/black stain reach the floor? Has water from the leaky roof made it down to the lower floors? I'd check that as well as you may find that the mould has spread beyond where you working.

[robertlennie]

Really - everything would need to get replaced - even if the outside only stays like that for a month or two?! I do need the room right away. I compl;etely agree with you guys - it is good advice to start fresh - but with limited time and budget - there has to be a way to do a decent job on sealing up what already exists. It's "easy" to rip it all down and start again - but I am looking for a more unintrusive answer.

New joists with a slope is a great idea - and since this was an addition, and they didn't tie into the old roof - I'll actually GAIN headspace. Although this way be out of my DIY abilities to tie into the old roof the ay it should be done considering all the angles, slopes etc.

The roof somehow is not leaking - even though I can see roof shingles through breaks in the existing planks. I'll definitely replace it in the spring. The black mold was in every wall and the roof - but the concentration was in the walls close to the floors. So, since it is above the eat in part of the kitchen - I can only imagine that the mold is creeping down the walls as well.

[Bumblerazz]

Well, if the roof isn't leaking and you need the room right away, I would do as you were planning. I would make sure the roof doesn't get too much snow it, especially as it is now starting to melt. I gather TO is on flood watch so take care.

Putting vapour barrier up over some batts will keep the mould spores from entering the room, at least while you wait for the weather to clear. You could try to bleach some of the mould as well using a soaked cloth or sprayer. If you do, use gloves, mask and safety glasses as bleach in the eye hurts like the devil!! :stickyman: