Now I need help, and I am grateful if you only respond to this if you are absolutely sure about what might happen.
We have due to uneven slab, downdraft at the sill. I.e., the sill probably does not fit tightly against the slab (could it be so?, or does the load from the house press the sill down making it tight?) Under the sill lies sill foam. Now to the question. What can happen to the house when it is like this? Can it cause problems (apart from it being cold on the floor and obviously costing money in energy)? Are there any good ways to solve the problem?
We have due to uneven slab, downdraft at the sill. I.e., the sill probably does not fit tightly against the slab (could it be so?, or does the load from the house press the sill down making it tight?) Under the sill lies sill foam. Now to the question. What can happen to the house when it is like this? Can it cause problems (apart from it being cold on the floor and obviously costing money in energy)? Are there any good ways to solve the problem?
Member
· Norrbotten
· 3 390 posts
With your nickname, you should be the one who can answer this 
Cold dry air seeping in at the sill is not likely to cause any other problems than the occasional spider or ant finding the passage. How is the house ventilated otherwise, new build, extension?
Cold dry air seeping in at the sill is not likely to cause any other problems than the occasional spider or ant finding the passage. How is the house ventilated otherwise, new build, extension?
Haha, right? In my world, not much can happen, but since there are two of us in the household and I represent the female side, my word doesn't carry much weight when the other resident has decided that the whole house will rot away because of condensation from the underfloor heating? And because warm and cold air can pass in and out under the sill? The house is newly built (2 years) and has Nibe 750 and regular fresh air vents otherwise. What do you think?
In my world, not much can happen, but since there are two of us in the household and I represent the female side, my word doesn't carry much weight when the other resident has decided that the whole house will rot away because of condensation from the underfloor heating? And because warm and cold air can pass in and out under the sill? The house is newly built (2 years) and has Nibe 750 and regular fresh air vents otherwise. What do you think?Thermal bridges increase the risk of moisture/mold, http://www.lfs-web.se/koldbryggor-fukt.htm. Whether there is a mold risk for you, I have no idea. I didn't understand the part about condensation from underfloor heating. The risk is more that the material inside near the thermal bridge/cold draft gets cooled, and the moister indoor air condenses on the cold surface.
A thermography would definitely provide concrete evidence. The cheaper option is an IR thermometer from Clas Olson to check if it is extremely cold. If it is colder than, for example, window frames (and they don't have condensation on them when it's the coldest), I wouldn't worry. Further inside the wall, it should be fine since there is constant underpressure and the moister indoor air doesn't get there.
A thermography would definitely provide concrete evidence. The cheaper option is an IR thermometer from Clas Olson to check if it is extremely cold. If it is colder than, for example, window frames (and they don't have condensation on them when it's the coldest), I wouldn't worry. Further inside the wall, it should be fine since there is constant underpressure and the moister indoor air doesn't get there.
Member
· Norrbotten
· 3 390 posts
Now we are not talking about a thermal bridge and condensation on the inside of a wall, but rather exactly the same conditions that the Building Inspector has with their fresh air vents, an airflow from outside and in (provided that the ventilation system with associated HRV is properly tuned). The pressure profile is also always such that at the floor there is an inflow of air, not outflow.
Is it a single point or is it around the whole house?
Is it a single point or is it around the whole house?