So my husband and I are trying to buy a 1829 Georgian Colonial (at least that's what I think it is.) The bones are great, lost of potential, and most of the work needed is cosmetic (and lots of it) but the scary bit is under the crawl space. The house is an L and half of it has a very usable full basement, while the other half, under the kitchen and laundry, is a 4'+/- crawlspace.

In this crawl space we found pipes with heat tape, wrapped batt insulation, space heaters, and a propane space heater with fire damage above it (just some singeing- no real damage), along with the water meter and *new* 200 amp electrical service. (Why new electrical in the crawl space, WHY?!). Obviously, we have a freezing pipe issue here. And I don't want to spend all my winter nights wondering if this is the night my pipes will burst. The foundation is a thick fieldstone foundation with a dirt floor and a solid fieldstone wall separates the two basement spaces. The boiler is in the full basement of course, like a reasonable person. There is some batt insulation in the floor above (ceiling?) But it's a very half hearted attempt.

So what is the solution? It seems that insulating the crawl space well might do it. But how best to do that? Some have suggested spray foam, but I have also heard that that might damage the foundation. Some have also suggested simply batt insulation, but that seems wholely inadequate. Some have said we have to go so far as putting a radiator in the crawl space to be sure.

Any adivce would be appreciated.

Thanks, Sara

Views: 13781

Reply to This

Replies to This Discussion

Ask the owners why all the different 'solutions' are there? what have they tried to fix? what didn't work?

I could make up a story that said in about 1978: 1) frozen pipes, 2) propane space heater to thaw pipes 3) use of space heaters the rest of that winter since it was too cold to really do any work 4) insulation which worked so-so 5) so heat tape added, and new electrical service because the house had only a 60 amp service... add in, perhaps, an over-zealous and inexperienced electrician. Since then the heat tape has worked just fine.

I am actually remembering 2 neighbors' frozen pipes as I write this. My story is only conjecturing - but while I think you are right to pursue this, I don't think you need to be too alarmed. Ask some questions first.

I once lived in a barn over an unheated, barely enclosed basement, where the cows had lived originally. We had to remember to turn on the heat tape, but it always worked.

You don't mention a hatch between the full basement and the 4' crawl space. In other cases I know of, that hatch allows heat to keep the crawl space from freezing - much as we open the doors under the kitchen sink to keep the water pipes from freezing on really cold nights. We have water pipes in our lower barn, for an apartment and my office. We keep the lower barn well sealed in the winter, but also build a tent around the water pipes and have a space heater for really cold spells.

I would also see if you could relocate the pipes very close to the floor of the room above and then box them in with solid insulation as well as passage into the main basement to allow heat in, or perhaps a grate with screening into the room above.

Your house if built in 1829 in Concord, MA, would be late Federal, early Greek Revival, maybe stylish, maybe farmhouse vernacular. Probably very solid post and beam, with 1" wood sheathing. Your wood cut with a water powered saw mill, up and down saw, not circular. Real plaster, mouldings based on Greek models - ellipses, not circles. Rumford fireplaces and maybe chimneys designed just for stoves. What fun!
I'm glad you have 4'! I have a crawl space with depths varying from 2' - 4.' Dirt base and all sorts of ghosties / remnants from years of weirdness with no real consistency of approach. Everytime I work the courage to go below I discover something new. Something ugly. Something mummified. Naturally, all the electrical is routed through the upper portion of the crawl space including 200A service. The electricians before (and current) probably saw this as expedient method and visually the least intrusive way to service all points. However, it is a nightmare tangle of Romex under select parts of the first floor. That being said most electricians who've visited the bowels don't seem bothered by what resembles a stiffened spaghetti serving gone awry.

As per insulation - the previous owner(s) had started installing pink insulation under the floor boards using chicken wire to hold it up. This was probably some 20 years ago. Over time the chicken wire has rusted out and nearly the entire run of the crawl space has hanging stalactites of pink fiberglas. A menagerie of critters tried to make a pocket homes in between the joists and fiberglas batting too. Little buggers! The little buggers also created runs to various portions of the floors until they encountered cross beams etc. The attic has rodent highways/breezeways well maintained by families of Rodentiae which have called the walls home. I've extracted many a stiffened carcass from order Rodentia: voles, field mice (meeses), shrews and squirrels. Of course, the flies and dermestid beetle larvae act a visible "bio" indicators which assist in locating the most recent corpse.

We've seen a dearth of insulation specialists and the obligatory Mass Saves rep. An insulation contractor who we saw recently suggested a few things which sounded reasonable and we were willing to contract services. For some odd reason he decided to bag out after forgetting and promising to bring a thermal gun as a part of the survey. Didn't help that his website advertised free thermal scan...wherein during the interview process we were told scans were an expensive add on service! Nice ethos to say one thing and split - but then again it is the world of contractors. Do anything, say anything - collect dinero.

In summary - the recommendations have been so mixed and much like the spaghetti tangle - hard to unravel. Foam it, don't foam it. Add more batting, add special foil batting, parge, add stiff styrofoam, add another separate furnace down there. It's now to the point where I don't trust anyone related to insulation. As I have issues with sagging joist the last thing I am going to do is spray foam down ($$$$) there making repair, or joist removal far more difficult when it comes time to repair.

So, the remedies for this season of cheerful heating is to install a new gas furnace 98.5 % efficient (replacing a 20 yr old Carrier unit which was inexplicably mounted in the attic, lethal to guests sleeping near a finished attic room) and to go down solo to the crawl space to add R19 batting to areas where there are gaps, plus adding more foam sleeves to where water travels.

This will be all good fun. Luckily I like spelunking, Daddy Long Legs spiders, but not inhaling bits of atomized rust from chicken wire. My wife said that she would help this time (again)- but on those days where I need the help she tends to inexplicably disappear. She's not set a single foot down there yet in over 1.5 years of ownership. Additionally, it helps that when I am down in the trenches I can't easily see her boogie off, as I can't squirm my way fast enough to intercept her when she has to take the dog for "emergency" walkies, shopping, or who knows what. That being said - I don't blame her. It is reverse hell down there. Cold & damp and ugly.

Anyway, I've found that a Tyvek suit is my best friend, as well these hangers which expedite the process immensely when adding R 19 insulation. I also have a superior quality mask, thick rubber gloves and wraparound eye shield on.

I do hope your crawl space is better than mine and that installation, or remedy comes easier.


Disgruntled Old House Homeowner Ken
Redo all the plumbing and put the pipes inside a "chase" that is enclosed as it passes through the crawl space, then set up a little fan or blower to move relatively warm air from from the basement in one end of the chase and through a duct back out into the basement. Set the fan to operate with a thermostat that has a sensor inside the chase, and a temperature readout upstairs so you can easily keep track of it.

I have made such chases out of wooden boards, and sonotubes. The sonotubes were slick and quick, but only suitable if the crawlspace is dry, since they are made out of cardboard. The last time we use a 10" diameter tube inside a 12" diameter tube forming a 1" trapped air space that acts like insulation.

This will cost far less than any scheme to insulate the crawl space, and have much lower ongoing operating costs than heating the entire crawlspace.

It's an "active" system, so you have to pay attention to it from year to year, checking and maintaining it to make sure it is operating correctly.

Terrific advice. Certainly beats everything I heard from a contractor trying to sell me stuff.


The pipe chases sound like good advice. The problem I have is that the water meter comes in at the floor at the furthest corner of the crawl space from the main basement. How do we create a chase for that? And get the warmer air to it? And they have to get into it to read it... Brings me back to the idea of insulating/heating the whole space or moving the water main to the basement and doing the chases, but that starts sounding expensive.

The pipes are kind of all over the place right now. On the ground, up near the floor and in between. We have both the kitchen sink and laundry pipes going through and the waste pipe goes out through the wall to a dry well. (the laundry and kitchen are on the dry well while the bathroom is on the septic) Don't know how much of an issue the waste pipes are for freezing.
From your original post it sounds like the previous owners left you with quite a mess. However that doesn't mean their idea was flawed, only their execution.

You can properly insulate the pipes with a high quality foam insulation along with a thermostatically controlled heat tape. This is the most economical solution which involves no new construction, no additional HVAC, and no alterations to your plumbing.
I would take the "easy" route and PROPERLY insulate the pipes with high quality material properly installed.  Then as John L. suggested, make sure there is air flow between crawlspace and basement.  
And there's nothing wrong with heat tape as long as it's turned on.  They make thermostat controls for heat tape so you won't have to worry about turning it on/off. 
I have some crawlspace areas of my house, where I added a utility room that has plumbing for laundry. The plumber wanted me to remove a basement window that connects that crawlspace to our regular basement, thus keeping the crawlspace warm enough for the pipes. I protested, because I was pretty sure that I would use a lot of heat into that space. My sense is that the soil in the crawlspace is frozen in the winter and thus conducts a lot of cold into the crawlspace. Basements are non-freezing, because the soil below them is below the frost line, so I think that any connection between a basement and a crawlspace is a recipe for a significantly higher heating bill. In my case, I had the plumbing routed through a longer distance in order to not pass through the crawlspace. So, I would try to avoid that option. John Leeke's chase system sounds like the best long-run plan, and I would just rely on heat tape in the short run. I think that the chase could go to the entrance point, then make a u-turn and come back along another pipe. That way it could be warm all the way to the entry point, but the air could still flow freely to that point, because of the return pipe.
Keeping a crawl-space as freezing cold as the outside may save you some heat loss from the basement.

However, it will then create more heat loss through the floor over the crawl-space.

It's probably close to a net zero gain/loss.

I'd rather have the floor in my living area (insulated or not) over a partially heated space than over a space as cold as the outside.
Phil writes:
"I think that the chase could go to the entrance point, then make a u-turn and come back along another pipe. That way it could be warm all the way to the entry point, but the air could still flow freely to that point, because of the return pipe."

Exactly so, circulating the somewhat warmer, above freezing, basement air.
Be cautious about insulating the floor joists above a crawl space

I came across an Internet article ( ) warning about floor joists rotting after insulation was applied incorrectly.

In case the hotlink becomes corrupted (try "copy and paste" into your URL box), go to
and read their articles about "Conditioned Crawlspaces,"
particularly the 2008 one titled "New Light in Crawlspaces."

I myself am researching about how to handle the dirt-floored cellar beneath my 1864/1870 brick Italianate.


Get Connected:

Follow Us on Twitter We're on Facebook!



© 2018   Created by Community Host.   Powered by

Old Houses | Restoration Products  |  Report an Issue  |  Terms of Service