Whatcha doin????

Discussion in 'General Discussion' started by TrustGzus, Aug 16, 2018.

  1. tango

    tango ... and you shall live ... Staff Member

    Trying to make sense of the usual tidal wave of information online about balancing insulation and ventilation.

    My hollow block walls look like they should breathe reasonably well but I'm bothered by air gaps around my soffits. Not only do they let in freezing cold air and noise but they also provide no barrier to insects. Part of me wants to fill them with spray foam but I'm hesitant because I don't want to find I end up with condensation in that gap and the resulting problems with the woodwork rotting. At the same time I'm cautious about not sealing the gaps because I don't want to find incoming airflow compromises the effectiveness of fiberglass that extends as far as the top of the walls. A large part of the concern is that there's a corner of the room that has no viable means of accessing the space from above, so if I get it wrong the only option is to tear down parts of the ceiling to have another go, with all the mess and disruption that entails.

    Needless to say there are some sites online that suggest the best option is as close to an airtight seal as possible while others warn of dire consequences of not allowing a lot of airflow. I just want to be able to use that room in the winter without finding the temperature dropped into the 40s again.
     
  2. IMINXTC

    IMINXTC Time Bandit

    Would be nice if you could rig up some shutter vents on top that you can close during cold weather. Like with pull-chains or switches accessable by ladder.
    Ventilation keeps your insulation dry and prevents moisture from seeping through the main structure.
    Maybe.
    EDIT: Something inspiring will come up.
     
    Last edited: Sep 24, 2019
    tango likes this.
  3. tango

    tango ... and you shall live ... Staff Member

    Shutters are an interesting idea. I'm not worried about rain water, more concerned about a possible build up of condensation and trying to think about the implications of airflow and moisture flow in summer and winter.

    If I could get shutters in there somewhere I think that would help - in the summertime the primary concern is rain hitting the west facing wall and being driven through the concrete by the heat of the sun. The concrete blocks are hollow, so hopefully the sun warming the blocks would also warm the air inside, allowing it to rise inside the blocks and get vented outside. I'm hoping any water that condenses inside the concrete blocks will evaporate as the air warms (the face of the concrete blocks inside the house often goes over 100 degrees in the summer, so it doesn't seem like a tall order). Then I just need to figure where to vent it to so that air can blow through and out.

    I'm really not sure what I'm trying to battle in the winter, other than a general concept of not wanting warm moist air to hit a cold surface and generate condensation.

    Since the soffit space looks like it goes all the way around the house, maybe I could rig something up so that warm air can vent through it in the summer but keep it closed up in the winter. Since the space goes all the way around the house it may be I can just seal up all the air gaps around the corner that's troubling me, let air vent through it, and put vents in the soffits that I can access from within the attic.
     
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  4. tango

    tango ... and you shall live ... Staff Member

    I'm thinking what I might look to do is drill holes in the attic floor, in the area the roof skirts out over the walls. That will mean the walls can vent into the attic. The attic is surrounded by a slate roof, so that offers at least some ventilation. In the summer it means the warm moist air can escape, and in the winter the moisture shouldn't be an issue. It will also mean I can spray foam to seal up the air gaps around the soffits, helping with the insulation.

    In the future if I decide to finish the attic space I figure I can build an inner wall and ceiling around the existing wall studs and rafters using insulation panels, tape the seams and corners, and then build an inner stud wall inside the panels. That will keep the cold out, hopefully keep the noise out, while also allowing air to circulate around the outside and over the top of the inner structure. Finishing the attic is a project that may never happen, I just want to have a loosely defined plan in case we do decide it's worth doing.
     
  5. IMINXTC

    IMINXTC Time Bandit

    Likely not a popular option, but a roof vent, one that is capped and with a self- propelled rotor would evacuate air upwards according to temps, allowing you to seal around the soffits.
    Floor and ceiling vents between stories can be shut and regulated to suit.
     
  6. tango

    tango ... and you shall live ... Staff Member

    Something in the roof could work, if it were designed to stop water and insects getting in. That's the sort of thing I'd pay someone else to do, our house is three floors counting the attic, so it's a long way down if anything went wrong. We have a slate roof all around the attic so the space can breathe, although if we ever do look to turn the attic into finished space the roof vent becomes a more attractive option. I'd imagine that putting a vent in the roof would be a straightforward thing for our roofing guy to do - it's a flat roof made of wood so a big hole saw should be about all that's needed, aside from the sealant to stop water flowing in around it.

    Vents between upstairs and downstairs aren't needed because the stairwell does that. Venting from upstairs to the attic is something I've often considered in the summer months. Years ago my father had an attic accessed by a hatch, so he took out the regular hatch and put in a custom one that featured a very large fan, operated by remote control. When he fired that thing up it sucked enough air through the house it would pull all the doors, upstairs and downstairs, closed. I've often thought of putting something like that in our house, we'd just need to figure out which windows are good to open so it didn't just suck in a load of exhaust fumes from passing traffic.
     
  7. IMINXTC

    IMINXTC Time Bandit

    Sealed roof vents are not expensive. As long as tree branches can't fall on them they seem to last forever.
    Escaping air causes them to spin so they don't let bugs or rain in.
    Installation - yeah. A roofer should be able to do it in less than a day,
    It's somewhat major, no doubt.
     
  8. tango

    tango ... and you shall live ... Staff Member

    Less than a day? I guess there's more to it than I thought, I was thinking a roofer would cut a hole in a wooden roof and fit the thing in an hour or less! Maybe it's a good job I don't do roofing...
     
  9. IMINXTC

    IMINXTC Time Bandit

    Well, with the slate, which takes some careful cutting.
    Or maybe not slate.
     
  10. tango

    tango ... and you shall live ... Staff Member

    The sides are slate. The flat roof on top is wood, covered with multiple layers of waterproofing material.
     
  11. IMINXTC

    IMINXTC Time Bandit

    Oh. Piece of cake.
     
  12. tango

    tango ... and you shall live ... Staff Member

    I managed to spray foam into most of the air gaps, although some of it oozed through the gap so now I've got a couple of patches of orange visible from outside which I'm really not happy about. One of them is in a place I can probably get at with an old kitchen knife taped to a pole, the other will need a big ladder. Maybe I'll talk to my roofing man to tidy it up and put some kind of other filler in the rest of the less accessible spaces, and while he's here he can put a vent in the roof.
     
  13. IMINXTC

    IMINXTC Time Bandit

    Major weather approaches this weekend.
    Snowo_O
     
  14. teddyv

    teddyv The horse is in the barn. Staff Member

    We had snow fall on the mountain; about 800 metres above town. Too early for that!
     
  15. tango

    tango ... and you shall live ... Staff Member

    Spent some time working on the trails I like to hike. Several of them are overgrown, badly in places. Technically it's the park's job to deal with it but they have been short staffed all year, so I told the park manager that if he'd let me use their tools I'd help clear them out. I hike them a lot, so I don't mind spending the time to make the hike a more pleasant experience.

    I thought the work I had in mind would take an hour, maybe a little more. Four hours later I was finally done, having walked a total of a little over six miles. Not all of it was trail clearing - once I'd cleared one trail to the end I turned around and came back so I could get to the next spur and clear that out. My second tank of gas ran out barely 100 yards from the end of the last trail I was working on. It's still passable, just a little overgrown - I got the parts I really wanted cleared out.
     
  16. IMINXTC

    IMINXTC Time Bandit

    Kicking back time - hooray!

     
  17. RabbiKnife

    RabbiKnife Open the pod bay door, please HAL. Staff Member

    Hey, Mountian Man.

    Ain't got no snow out there, have you?
     
  18. IMINXTC

    IMINXTC Time Bandit

    We got hit the least in the valley while all around us it's about 1 to 2 ft.that stayed.
    About 30° F.
     
  19. teddyv

    teddyv The horse is in the barn. Staff Member

    Pretty impressive snowfall for this early out in Alberta. Glad that it missed us further west, although it has been getting cold at night now.
     
  20. tango

    tango ... and you shall live ... Staff Member

    It's colder here than I'd expect for the time of year. Usually September is pretty warm but this year we've barely used the air conditioners at all in the last 2-3 weeks. I hope this doesn't mean a long and hard winter is coming.
     

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