Risks of failure in radiant slab heated housing 1960 vintage

DickN

I am interested in purchasing a house built in 1960. The heat is radiant in the slab for the ranch style house. It is a "Campannelli" slab house in Framingham MA - I think this construction may be similar to the Levittown house design.
I have never owned a house with radiant heat - all my houses have had basements with hydronic oil fired systems.
Also this system is over 50 years old.
Can I expect to replace it in a matter of 5 years or so?

Gordy

Honestly it's a crap shoot. I own a home that is over 63 years old with radiant in the basement slab. Ceiling radiant in plaster.

The crap shoot is high fly ash ratio concrete, aggressive soil, and water quality in the system. Also type of piping in the concrete. I would say find out if it has leaked, or is leaking. If there was never an issue past or present could last another 20 years or more.

aircooled81

I did 4 years of slab retrofit for a college campus nearby. The condos were built in the 50's, this project started 12 years ago to retrofit this aging system, remodeling 10 to 14 buildings a year. Most commonly were pipe leaks that required concrete removal to repair and were not cost effective. Most buildings showed no signs of leaks.
Due to the zoning, disabling a leaky zone ment losing heat to half an aprtment.
So the radiant heat was capped, and left burried. We installed convectors on the exterior walls and routed all the piping in walls and ceilings. Able to reuse the boilers and pumps.
So, the moral of that story is, slab reheat has a lifespan, hard to say if yours will last more than 65 years.?


Another note, many floors were resurfaced through this remodel procedure, due to the slabs being cracked. Pull up a bit of carpet and see how much the earth has moved under this house your gonna buy.

SWEI

A pressure test is not a complicated thing to perform. Write it into the offer, or simply disclose after the inspection. Get a price for installing wall radiators and new piping and bring it to the negotiating table.

hot_rod

How badly do you want that home?
No doubt you are on borrowed time, and at best if it works it is probably very in-efficient. There was not a lot of attention paid to insulating in those days.

At the very least get some ideas what a retro fit new system of some sort will cost and bring that to the table, as Kurt mentioned.

Does it have or need AC in that area? Consider that when you get options for a new system.

pecmsg

DickN said:

I am interested in purchasing a house built in 1960. The heat is radiant in the slab for the ranch style house. It is a "Campannelli" slab house in Framingham MA - I think this construction may be similar to the Levittown house design.
I have never owned a house with radiant heat - all my houses have had basements with hydronic oil fired systems.
Also this system is over 50 years old.
Can I expect to replace it in a matter of 5 years or so?

http://www.oldhousejournal.com/radiant_reflections/magazine/1396

Bob Gagnon plumbing and heating

I would pressure test the system as part of the home inspection, then I would try and work the price of installing baseboard in the place of the Radiant, but if the fuel bills aren't too high I would use the radiant as long as it lasts, if there's no leaks now, it's a good bet you might go 5 or 10 more years with the radiant.

Thanks, Bob Gagnon

stephanies

I’m looking at same issue with a campenelli ranch purchase  in Framingham.  Radiant heated  with oil  about to crap out. What did you end up doing , Bob? I’m just looking for an affordable home and don’t want a massive repair project. 

Stephanie

Mad Dog_2

Don't let it stop you from buying that home. Use it as leverage to get a few bucks off.... just  In case.  Might keep working for years.  There still quite a few Levitts working   Mad Dog 🐕 

hot_rod

stephanies said:

I’m looking at same issue with a campenelli ranch purchase  in Framingham.  Radiant heated  with oil  about to crap out. What did you end up doing , Bob? I’m just looking for an affordable home and don’t want a massive repair project. 

Stephanie

How do you know its about to crap out?

pecmsg

hot_rod said:

stephanies said:

I’m looking at same issue with a campenelli ranch purchase  in Framingham.  Radiant heated  with oil  about to crap out. What did you end up doing , Bob? I’m just looking for an affordable home and don’t want a massive repair project. 

Stephanie

How do you know its about to crap out?

X-2

propmanage

If you like and want the home, then ask them about bringing down the price a little so you can add a back up heating system. Maybe a couple ductless heat pumps just in case you see an increase in makeup water in the middle of winter. They are buried in cement so if the line fails you may not notice it right away until you start seeing lots of air in the system and a drop in performance.

hot_rod

On older at risk tubing like that adding an Axiom filler tank might be a good idea. It lets you know if makeup water is being added. Before the water and gas bill tell you.

mastercraft

I work in this area & familiar with the campinelli homes.   Have replaced several & abandoned in place the radiant under floor piping.   We’ve put oil fired  boiler in garage & ran new baseboard.   (Need parking poles for protection & boiler must be 18” above floor).  The other option Is to add a hydro-air system in attic & use one loop of heat to air handler.  Now your world have both central heating & with added outdoor condenser central air conditioning.  

mastercraft

As an aside.. in the 80’s I was taught to look for underfloor leaks by where the cat slept, they love those warm spots!  

Geosman

I've made repairs to several 1950s era systems. Most leaks were around the bath toilet flange where moisture could accumulate in the slab. They were not difficult leaks to reroute but required pulling the toilet and carefully taking up the concrete to expose and pipe around the problem before resetting the toilet. Locating the leaks was a challenge. It meant isolating the manifold from the boiler and using high pressure air along with a ground phone to listen for the escaping air in the slab. I've paid for that ground phone several times over locating frozen radiant lines in foreclosed homes that were not winterized. They are all back in operation as though there were never any problems.
As others will likely say, just wet mop the floor to reveal where the lines are set. The wet floor will dry fastest above the warm lines. This way you can take a photo for reference if you need to investigate further.
For small leaks where it may take several days for the system pressure to drop, I've used a solution called Loop Conditioner. It's used by geothermal contractors as well as pool and spa people to seal minor underground leaks.
https://www.amazon.com/GEOLOOP-LEAK-SEAL-Geothermal-oz/dp/B073WN2CCK/ref=asc_df_B073WN2CCK/?tag=hyprod-20&linkCode=df0&hvadid=216508137554&hvpos=&hvnetw=g&hvrand=3763697903649294232&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9014416&hvtargid=pla-350530173996&psc=1
I've had great success with this product to seal leaks in old polybutylene radiant heat where taking up a wood floor over the concrete was not an option. Again using it required isolating the manifold from the boiler and using an external pump with hoses to pressurize and recirculate the fluid for several days before placing it back on the boiler. That one has been running now for the past 4 years with no further issues.
Another option I've used on a high temperature glycol system for a green house was Hercules Leak Seal it too has worked very well for sealing minute thread leaks that would normally be a royal pain to break and re-pipe.
https://www.supplyhouse.com/Hercules-30-115-1-qt-Boiler-Liquid-4101000-p?utm_source=google_ad&utm_medium=shopping_neutral&utm_campaign=Shopping_Neutral_New_users&gclid=CjwKCAjwyNSoBhA9EiwA5aYlb47BW07Zza9L_sZZqfFM7-sVsqxqqucpFZINPpKc00DYS2D5tHDFERoCAlkQAvD_BwE
Best of luck with your home purchase. There is light at the end of the tunnel and its not necessarily the train :-)

bburd

Regarding the suggestion to heat an older slab on grade home in a cold climate via hydro air from the attic, this  is almost guaranteed to create a very uncomfortable living space with cold floors and significant temperature stratification. There is good reason why the heat source was put in the floor in the first place. Those old slabs were typically not insulated.

Baseboard heat will be far more comfortable.

hot_rod

Panel radiators are a nice option. You get some of the radiant feel from themt hat you will not from fin tube.
Easy to zone with TRVs that you can reach without bending over.

OuterCapeOilguy

Years ago (around 1992-93) when I lived in the St. Louis area, I was called into a 1930s-era home with copper-tube radiant in the terrazzo ceilings of the main floor (in the floors of the 2nd story), not heating. Some genius had turned the aquastat up to around 220º as a "solution" to the problem, which obviously didn't work but did help the bottom line of Laclede Gas. Turned out that almost all of the various shutoff valves in the system, old fashioned washered valves, had leaky, worn and almost non-existent valve stem packings which allowed air into the system, along with a defective PRV. It took me the better part of the day to repack the valves and replace washers, along with a new PRV (and an up-to-date expansion tank/air scoop combo), but once done and the aquastat set to a more reasonable 160º, the system worked like a champ. I never got a callback for the remaining 18 years I lived in the area, so I'm guessing that the copper tubing was not affected by the terrazzo. Since you're dealing with concrete, I suppose it would depend on the makeup of the concrete, but concrete can be problematic with copper tube.

If it's working now, just keep an eye on it; if you begin having problems with air in the system or unusual water usage, there's likely a leak. An Axiom DMF150 make-up water system provides a good way to alert you to an increase in make-up water usage (normally there should be none), but is somewhat expensive. Meanwhile, you might want to put money aside to convert over to a baseboard/panel radiator/wall convector system if you do run into compromised radiant tubing.

mattmia2

hot_rod said:

On older at risk tubing like that adding an Axiom filler tank might be a good idea. It lets you know if makeup water is being added. Before the water and gas bill tell you.

Or put a water meter on the makeup water feed.

jumper

hot_rod said:

Panel radiators are a nice option. You get some of the radiant feel from themt hat you will not from fin tube.
Easy to zone with TRVs that you can reach without bending over.

I second this suggestion. Something to think about is smaller panels and hotter water. Theoretically less efficient but in real life?

Kirk Shriver

Everything is a negotiation. I would suggest that you try to know more than the other party in order to get the best contract.There are many possible systems to use for replacement while leaving the old system buried, radiant floor on top of the concrete, radiant electric ceiling, and mini-split heat pumps which add A/C to the mix.

RandandReardon

I am in Beverly Mass and have worked on Campanelli homes. My town has two of these developments. My guess is that 50 years old may be a little modest. As others have mentioned, sometimes the tube fails due to chemical reactions between the tube and the concrete and fillers in the concrete. The tube often fails when the tube enters the concrete due to fatigue. The tube encased in the concrete cannot expand whereas the tube outside can. The highest point of stress is right on top of the floor. The systems were designed with a 20-year life. So that system is on its third of fourth lifetime. It doesn’t owe anyone anything. With the Mass Save rebates I would consider retrofitting the house with mini split heat pumps right away. Long term you could retrofit with baseboard but why keep the oil? I would be more worried about a 50-year-old oil tank and having a boiler in my kitchen or a closet.

EdTheHeaterMan

Short answer to:

Risks of failure in radiant slab heated housing 1960 vintage

HIGH

hot_rod

Oh it's gonna fail alright. The challenge is predicting when.

mattmia2

hot_rod said:

Oh it's gonna fail alright. The challenge is predicting when.

You could say that about any boiler as well.

hot_rod

mattmia2 said:

hot_rod said:

Oh it's gonna fail alright. The challenge is predicting when.

You could say that about any boiler as well.

And about you and me also

EdTheHeaterMan

hot_rod said:

mattmia2 said:

hot_rod said:

Oh it's gonna fail alright. The challenge is predicting when.

You could say that about any boiler as well.

And about you and me also

I already know when I'm passing. My birth certificate has an expiration date!

lowercanada

OuterCapeOilguy said:

Years ago (around 1992-93) when I lived in the St. Louis area, I was called into a 1930s-era home with copper-tube radiant in the terrazzo ceilings of the main floor (in the floors of the 2nd story), not heating.

what the heck is a "terrazzo ceiling"?