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drockee | Posted in Energy Efficiency and Durability on

MY house was built in 1896. I believe thiere is some type of wall insulation, as cold walls are not my problem. On one outside wall of my house, I can feel cold air drafts between the floor and where the wall hits the floor. It is not coming from the basment as it is cold air, and the floors in the basement along the walls have insulation. I am suspecting it is coming up under the siding and then into the house. There is a gap at the bottom of the siding where it hits the foundation. What kind of insulation can I stick up under the siding to see if this will help? I assume something that might be resistant to moisture, etc.

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  1. dankolbert | | #1

    Have an energy auditor do a blower door test.

  2. charlie_sullivan | | #2

    A blower door test is a good recommendation. A stop-gap measure (literally!) would be to caulk the crack that is leaking air, from the inside. But if there are likely other less obvious leaks that are losing heat as well, which is one reason a blower door test is a good idea. For example, if there are leaks into your attic, that's part of the problem, but you won't feel cold air there so you might not notice.

  3. Expert Member
    Dana Dorsett | | #3

    Don't seal up the bottom of the siding, seal up the bottom of the SHEATHING. Most wood siding clad 1890s house had plank sheathing with or without rosin-paper or tar paper between the siding & sheathing, which makes it something of an air-barrier & drain plane. The seam between the sheathing and the foundation sill still needs to be caulked, and the seam between the foundation sill and foundation need to be sealed too. On ballo0n framed buildings this is often easier to do from the interior side (basement or crawl space, in which case 1-part can-foam works pretty well. If doing it from the exterior using caulk is better, since it won't expand and potentially block the drain plane, causing bulk moisture to collect in the bottom plank of sheathing, foundation sill, and bottom course of siding.

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