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Internal wall of a 1835 house

Riccardo La Rosa | Posted in Energy Efficiency and Durability on


I live in a greek revival house built in 1835 on Cape Cod (MA). Over the years this house has gone through different renovations/updates some more successful than others. We are in the process of renovating the top floor which still has original wood windows (in really bad shape unfortunately) and no insulation.

The house uses post and beam construction (I was told) and the side walls (East and West facing) don’t have any cavity. The North and South walls (front and back of the house) do have cavities and have been insulated with cellulose 3 years ago.

The current wall configuration for the East and West side is (from outside to inside): shingles, asphalt felt, 1in thick wood boards, lathe and plaster. So the lathe and plaster are attached to the inside of the wall board.

We want to build the inside of these walls (on the east and west side) to add 2×4 or 2×6 frame and then insulate them (after we redo electric system).

My question is if I should remove the plaster before building the new internal walls. Trying to understand if the mess of removing almost 200 yrs old plaster is necessary or if I can enclose it in the new wall structure.

I hope I explained this clearly. Thank you in advance for your advices.

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  1. Expert Member
    Dana Dorsett | | #1

    Stripping it back to the plank sheathing would be best practice, and would give you a chance to assess if there are any moisture intrusions that might need to be addressed first. Right now minor amounts of moisture blowing by the shingles during an nor'easter can dry toward the interior pretty quickly, redstributed by the plaster & lath, and may only show up as small sections of failing paint. Once you close it up it'll stay there- the plaster & lath is akin to having a coating of stucco, which can absorb quite a bit of moisture , enough to be a problem for the (as yet unbuilt) insulating studwall.

    Walls that old almost certainly have some layers of leaded paint- so treat it accordingly during all phases of your project.

  2. Riccardo La Rosa | | #2

    Thank you Dana for the insights.
    I can't believe I forgot to mention lead in my post. That is one of the other reasons why I was hoping to not touch the plaster. But like you said, not a good idea in the long run.

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