What would you recommend for the uninsulated exterior walls on my 1938 row home in Philadelphia?

Asked by Nyanya Pospolyta
Philadelphia, PA

I purchased a 1938 row home in Philadelphia and it has no insulation. Walls are plaster and lathe. Would replacing the vinyl siding with insulated siding help with energy costs?


Sean Lintow Sr

Answered by Sean Lintow Sr

Naperville, IL

SLS Construction & Building Solutions

April 22, 2013

That is a very good question, yet hard to answer without knowing all the
about your house and its construction.  In fact if I think back, most of the row houses I saw in Philly had brick exteriors with very little area for siding if any. 

With that and in short, insulated siding is a joke for the most part and probably won't help you reduce your bills contrary to some of the claims out there. 

You really do need to have an experienced energy auditor come in and look at everything at once and present you your options. 

While there are many types of audits, you want one that will be using a blower door, infrared, and a snake cam.

  • If your exterior is not brick, the auditor may call for removing the vinyl, taking it down to the sheathing & adding R10 or more on the exterior.
  • The auditor may even open it up further and after dealing with any electrical issues (do not insulate around knob and tube or older type wiring) they may dense pack those areas.

Assuming the outside is brick, if they determine (or you fix) any electrical and/or water infiltration issues the auditor may recommend drilling some holes in the plaster and dense packing it with cellulose.


For more information:

Read "We have inadequate wall insulation. What is the best approach to insulate our walls?" a Q&A answered by Michael Holcomb.

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