# 100 year old house & insulation



## DianneB (Aug 7, 2014)

My house is almost 100 years old, a pioneer story-and-a-half house build before building codes. Most of it was built with trees sawed flat on one or two sides (as required) and sheeted on each sides with 3/4" rough cut planks. It was cold and drafty when I bought it in '97 and I replaced the cedar siding with 2" of SM from 2' below grade right up to the roof sheeting (with parging and trim boards to look like half-timber construction).

I didn't see as much reduction in my heating bill as I had hoped and one part of my living room ceiling was VERY cold any time there was a northwest wind. After a record cold winter this year, I decided to go at the second floor and find out how the wind was getting in.

There were vents on each end of the attic space and very little insulation (wood chips) between the rafters but no provision for air flow under the roof sheeting and no vapour barrier. The knee walls and much of the 3/4" plank sheeting was rotten and mouldy so I ripped everything out to the rafters on the north 1/3 of the upstairs. I put up new knee walls with 12" of 'cold zone' behind them, used "Rafter-Vent" against the roof and 3.5" of fibreglass bat to allow air flow from the cold zone to the attic space but have not yet provided an air inlet behind the knee walls.

When I got to the centre 1/3, I found that a "built-out" section (that includes mt living room) has ZERO insulation over the living room ceiling and no vapour barrier - no wonder that area was cold! The winter wind blew in through the attic vent, down between the rafters, and out in the spaces between the hardwood ceiling below! Because there is a dormer above, this 'extension' roof is very low slope and I don't think I will be able to get in there to add vapour barrier and bat insulation so I may have to go to spray foam.

The space above the living room ceiling will also be a 'cold zone' and will communicate with the space behind the knee walls on each side but I still haven't figured out how to get fresh air into this space!

Initially I was considering putting a shuttered and screened vent in the end walls of the house that could be opened in the summer and closed for the winter but these vents would be almost 15 feet above grade and not that easy to get to.

I could put one or more roof vents on the low-slope roof over the living room but that area tends to pile up with snow.

I could put roof vents in the rest of the (NEW!) roof over the cold zones but it is steep and they would have to withstand sliding snow. I have also seen wind-driven snow blow in through roof vents and leave a snow drift in the attic! (NOT GOOD - especially when the snow melts!)

Any other ideas?

(Sorry the site wouldn't let me post pictures in-line - my post would make more sense if it did!)


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## jknmcd (Aug 7, 2014)

Nice job, should make a big difference...


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## Windows on Wash (Aug 30, 2011)

I think you are on the right track.

You can scab down the sloped sections and create your own vented space with rigid foam.


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## DianneB (Aug 7, 2014)

Windows on Wash said:


> You can scab down the sloped sections .....


What does "scab down" mean?


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## bilug (Apr 16, 2014)

Very neat old house. More pictures would be great!


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## Windows on Wash (Aug 30, 2011)

DianneB said:


> What does "scab down" mean?


Artificially increase the depth of the joist cavity so that you can get more insulation in.


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## DianneB (Aug 7, 2014)

I _could_ have used rigid foam but cost per R-value is much higher and I don't gain very much in the available space. I also didn't want to loose head-space under the sloping ceiling.

The main complicating factor is that the rafters are set INto the walls, not on top of them so I can't use soffit vents. That DID allow me to take the exterior SM right up tight against the roof sheeting to provide a continuous layer of insulation and vapour barrier.

It is almost a shame to create a 'cold zone' behind a well-sealed wall but that's why I would like to use some kind of shuttered door to allow air into the cold zone during the summer to help keep the second story cool but to close it off in the winter to keep as much heat in as possible. The fun part is that these 'doors' would be about 15 feet above grade and would (ideally) be remotely operated so this old lady doesn't have to go around with a ladder twice a year to open and close them! :huh:


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## Bob Sanders (Nov 10, 2013)

I have a 100 year old house just like your. I look at the second floor and it looks EXACTLY like mine when I first moved in. Funny, when I opened up the roof space to insulate like you have, I found old newspapers and magazines stapled up on the underside of the roof for insulation Some of the dates on them were from as far back as the late 1800's. Amazing the stuff you find inside these old houses... and building codes... forget it! You open up some of these walls and it's like the builder tried some completely different with each passing day.

Anyway, the first couple of years living in the place, the heating bills were just awful. After the second floor space was insulated the bill was better, but what made a substantial difference was new wall insulation from the outside. The biggest problem with the older houses are all the air leaks. When it was windy ouside you could acually feel a slight draft in the house. You can never get all the air leaks from the inside and since my siding was bad I elected to do 1.5 inch Styrofoam on the outside (all seams sealed with tuck tape) and then siding over that. Big difference!

Your end window on the second floor...
I did a rake head cut. You should do that. It looks neat from the outside and in (my daughter's room... sorry for the mess!)













(I also push the roof line out on the left side for increased size)


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## DianneB (Aug 7, 2014)

That's a NEAT window Bob! I like the way it opens things up. New windows are beyond my pension but I like it.

How did you structure to carry the ride load from the roof?

I haven't got any farther than the plywood walls so far but with most of the rotten old wood gone, it smells fresh. Hopefully this fall I can finish gutting the rest of the second floor and get it insulated and sheeted as well.

Before I started, my 20KW electric furnace couldn't hold the temperature on a cold, windy day - the house would keep getting colder and colder! 

I did my exterior with 2" ship-lap Styrofoam SM directly over the bare planked outer walls with PL-300 adhesive, 3" screws, from 2' below grade right up tight to the roof boards and then trim boards and "Parge-All" over the SM, a special parging that bonds directly to the SM. It's pretty well sealed, like one continuous layer of 2" SM!

I am glad to know there is _someone_ else out there who understands the challenges of century houses! :wink:


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## Bob Sanders (Nov 10, 2013)

DianneB said:


> How did you structure to carry the ride load from the roof?


Just added a couple of 4x4 headers in at the roof line.

It's a lot of work, but worth it. I love the older houses. IMO, they have a lot more character than the newer cookie-cutter type houses you see out there today.

keep up the good work!


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## Windows on Wash (Aug 30, 2011)

Looking good Diane and Bob.


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