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Insulation a foundation externally

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  • Insulation a foundation externally

    Denmark is a place where heating is required during the winter period, typically October to March.

    A lot of older houses have little or no insulation of the foundation. Space heating disappears into the ground and outside air, while the floors inside are too cold. If you are in a climate with snow, it is easy to tell if your foundation needs insulation: When the first snow falls, does it melt around the house? Before I did this renovation, the snow typically started to several meters from the wall. Only with many days of extended snow, the snow would reach to, and touch the wall. Guess where the energy came from, to melt this snow? After the mod you can see below, at first snow, the snow remains up to and up against the foundation. See the link to the video also, where you can see the neighbor house, without this socket mod.

    In October 2010, I dug around the foundation of this house, and placed 2 x 100mm styrofoam type of insulation, offset to prevent leakage. So a total of about 2/3 feet. Since the foundation of this house is above ground by a bit, we extended the insulation up to and including the lowest row of bricks.

    Because of the solar thermal install to be made, we even added a pipe in the outside of the foundation, to enable solar heating of the foundation. On the INSIDE of the foundation. This makes sense because there are often solar thermal energy available that cannot be absorbed elsewhere. Either because the temperature is too low, or because it isn't needed. Or other heat storage are already too hot.

    Anyway, these pictures show a bit about how it was made. Note that this is a course from 1980, a renovation. New houses already have requirements in most countries for being insulated to certain standards.

    WARNING: When you are making a renovation like this, be very careful that you don't dig up the whole foundation and the house sets. If in doubt, ask someone to help who know enough about these things. If you only dig up a short section of foundation at a time, then finish it, then the rest of the foundation can carry more. It will also depend how far down the foundation goes. Do not dig too far down, or below the foundation. Or ask a building engineer for advice.

    Click image for larger version  Name:	2011-10-13 17.14.22.jpg Views:	2 Size:	1.08 MB ID:	178

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    Click image for larger version  Name:	2011-10-22 13.34.46.jpg Views:	2 Size:	1.20 MB ID:	177

    It looks like massive concrete, but in reality it is just a shell of concrete (on a steel net), covering the styrofoam.

    Does it work?

    Have a look here:

    It saves a lot of space heating, and the floors are now comfortable to walk on on the ground floor also, even when being barefooted.

    Compared to breaking up the floor on the inside of a building, this is some times a better and faster solution.

    Place styrofoam
    Cut to fit
    Cover in steel mesh
    Clad with concrete.

    After 12 years, it still looks great, with only minor and minute cracks of no significance.
    Last edited by Core; 09-06-2022, 12:17 PM.