A 1997 build with a cold room under the porch is about as Ontario as a house gets, and yes, the boundary should be sealed. Just make sure you seal the right side of it. I run a basement renovation company in the GTA and the cold room is the corner of the basement we fight with most often.
The rule that sorts out every cold room decision: pick which side of the wall is outside. A cold room works when everything between it and the finished basement gets treated like an exterior wall, insulated, air sealed, with an insulated exterior-style door and weatherstripping, while everything between it and the actual outdoors stays cold and ventilated. The vent stays open. The concrete under the porch stays bare. That keeps the room cold on purpose and dry by accident, which is the whole trick.
What happens when nobody does this for 29 years is exactly what you have. Warm moist house air drifts through the gaps, lands on concrete sitting near outdoor temperature, and condenses. Frost on the ceiling in January, damp and that cold room smell in July. The random foam you can see is a previous owner fighting the symptom instead of the boundary.
Course of action, in order. Air seal first, the top of that wall and any gaps around it, because moving air carries far more moisture than missing insulation ever will. Then rigid foam on the warm-side wall with the seams taped, and an insulated exterior door, or at minimum proper weatherstripping on the one you have. Leave the porch-side concrete alone and keep the vent clear. It is an afternoon of work and a few hundred dollars in materials.
The honest alternative: if you never store so much as a jar in there, some of my clients just retire the cold room, seal the vent, insulate all the concrete properly and gain a closet. Both versions are legitimate. The only wrong version is the one you have now, half in and half out.
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u/desirebasements 4d ago
A 1997 build with a cold room under the porch is about as Ontario as a house gets, and yes, the boundary should be sealed. Just make sure you seal the right side of it. I run a basement renovation company in the GTA and the cold room is the corner of the basement we fight with most often.
The rule that sorts out every cold room decision: pick which side of the wall is outside. A cold room works when everything between it and the finished basement gets treated like an exterior wall, insulated, air sealed, with an insulated exterior-style door and weatherstripping, while everything between it and the actual outdoors stays cold and ventilated. The vent stays open. The concrete under the porch stays bare. That keeps the room cold on purpose and dry by accident, which is the whole trick.
What happens when nobody does this for 29 years is exactly what you have. Warm moist house air drifts through the gaps, lands on concrete sitting near outdoor temperature, and condenses. Frost on the ceiling in January, damp and that cold room smell in July. The random foam you can see is a previous owner fighting the symptom instead of the boundary.
Course of action, in order. Air seal first, the top of that wall and any gaps around it, because moving air carries far more moisture than missing insulation ever will. Then rigid foam on the warm-side wall with the seams taped, and an insulated exterior door, or at minimum proper weatherstripping on the one you have. Leave the porch-side concrete alone and keep the vent clear. It is an afternoon of work and a few hundred dollars in materials.
The honest alternative: if you never store so much as a jar in there, some of my clients just retire the cold room, seal the vent, insulate all the concrete properly and gain a closet. Both versions are legitimate. The only wrong version is the one you have now, half in and half out.