Big Old Houses - Part 2

April 6, 2007 by Jeff.

A little background on my father-in-law’s house: It’s a typical 1880’s wood frame, 3 story city house – narrow and deep, wood sided, slate and tin roofed. With 6 bedrooms, 3 bathrooms, parlor, living room, dining room, back wing and various closed-in porches, it’s a prime example of too much house for modern times. Be that as it may, we need to keep it comfortable without breaking the bank. Oh – and did I mention the complete lack of insulation?

Last time I talked about managing heat production. We’re adding a setback thermostat. We turned off the radiators and closed the doors of unused upstairs rooms. I would normally recommend adding zoned heat. He currently has one heating zone – one long loop of pipe servicing all the radiators. If he could put up with the mess and disruption, I would advise him to add 2 more zones – splitting the downstairs living and sleeping areas into daytime and nighttime zones and adding a separate zone for the 2^nd floor. Each zone would have its own thermostat. Figure 15% less on that monthly $500 heating bill.

The mantra for heat is “if you don’t lose it you don’t need to buy it”. Air changes (outside air coming in) account for most of the heat loss in older houses – some are so badly sealed that their air exchange rate (how many times the inside air volume is replaced by outside, unheated air) can exceed 20 per hour. So step-2 of the long-term plan is to do a thorough job sealing up the house.

Remember the air conditioner in the window? That’s one big hole to the outside. We need to take it out. Then it’s time to close and latch all the storm windows. Although double hung aluminum storms are not great, they are better than nothing and at least keep wind pressure away from the windows.  There are quite a few hanging open a bit, or just not closed at all.

Old double-hung windows suffer from a multitude of ills. We’ll discuss them in a future post. For now, let’s just say that we use weatherseal tape (plastic tape that doesn’t harm paint) to seal all the windows on the second floor and the tops of the first floor windows. Why don’t we seal the bottoms? We want them to open easily in case of fire. No one is living upstairs, so we can seal those windows completely.

It’s an old house. Lots of doors, none of them well sealed. My preference is to install insulated fiberglass doors, but that’s a job for warmer weather. So for now we add foam weatherstrip to the outside doors and make sure the storm doors latch properly.

Let’s move outside. Hose faucets and other wall perforations get caulked or filled with expanding foam, depending on their size and location. Keep in mind that sunlight destroys the foam, so don’t use it in exposed areas – it will get brittle and fall apart. Window casing gets caulked both at the wall and where the storm window frame hits it. We never, ever caulk the bottom of the storm window frame – it needs to be left open to let rain seep out. While we’re at it, we clean the seep holes to make sure water doesn’t build up and rot the wood.

Next time: What do to about old windows…

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