Randy in Maine
Well-known member
With at least 2" of insulation under the concrete.
To Spray or not to Spray(foam)
- Thread starter JohnnieMo
- Start date
With at least 2" of insulation under the concrete.
I'm glad so many brought up in floor heat...... now I don't need a new thread!
Originally I was just going to expand the pad on the existing garage, however I think I'll have cheap access to a bobcat and trailer so I can pull it out and start new.
So some questions about in floor radiant:
1) How do costs compare for materials? I assume I need a small water heater now instead of a big furnace. (or radiant tube heater). I had $1500 in my plan... so can I install the radiant system for this amount?
2) The left side of the garage is mostly storage while the right is the workspace. Can I install separate zones to adjust the heat?
3) Everyone says 2" under slab insulation.... what type?
Running all the pex will be a nuisance but I love the idea of having warm feet.
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I did find a local fabricator of SIPS. Www.titanwall.com. I'll run my plans by them and see what they say.
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rancherbill
Well-known member
???
Electrical is IN the wall. Gas and air ARE NOT IN the walls.
Frame it, install windows, doors and Tyvek and you have a basic water wind barrier. Don't put anything in the garage. Do electrical and then spray or use fiberglass. If you use fiberglass, installing a vapor barrier, batts and blown in stuff is less than a day for 2 people.
Then add OSB or drywall. I chose drywall because it is attached and by the time it's truly finished it will be an 'Air Jordan' garage not a dirty car house.
DC73
Well-known member
Yeah, you Canadian guys have a different brand of cold. And you let some of that cold escape down to Texas this week. Take it back!
The point I meant to make is that regardless of what is happening at the doors, I wouldn't let that impact my decision to well insulate the rest of the structure. The better the rest is insulated, the easier to manage the cold through the doors.
DC
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Randy in Maine
Well-known member
The 2" foam everyone around here uses to insulate the floor and frost walls is the blue stuff from Dow. Here is it $1 per square foot inside the foundation.
Also around here most overyone uses 1/2" pex tubing placed 12" OC with pretty much equal loops of about 250-300 feet. Buy 1' foot of 1/2" pex per square foot of foundation. My shop was build on grade ans does not have any rebar in it, so I put some masons "woven wire" (6" x 6" wire) down there to attach the tubing to. Worked great. Don't overthink the radaint floor heat as you are essentially heating a rock using warm water just like the Romans did. It is a rock and mine is about 42 tons of thermal mass concrete and will average it out.
My shop just uses hot water from my house propane fired Baxi boiler for the heat that is on it own zone. 3/4" pex to and from to my shop in underground PVC. I converted the whole house to radiant heat on demand while I was building the shop. Money well spent. I didn't use any antifreeze in my radiant set up, but I would have to lose power for a long time in real cold weather for that to be a problem. I could run the whole thing off my little generator if I had to.
My shop is 6" of 4000 psi concrete. Where my 2 lift posts go, I exchanged the 2" of foam for an additional 2" of concrete with no pex for 36" all around each post location on advice from BendPak. My concrete guy was very good and the top foundation elevaton was within 1/4" from high to low. I was impressed.
My buddy is one of the local bulding inspectors and he was a great asset in giving me good advice on the SIPs and the radiant floor heat. His advice was to buy the good panels, run the wiring in conduit surface mounted, and buy the Upanor O2 barrier pex tubing even though it costs a little more. My heating guy and the electrician also went out of their way to do good quality work.
Find somebody like that near you. Every place is a little different. If your SIPs guy wants to show off your building for future customers, use that also to your advantage. It gets cold here in Maine, but it is probably colder where you live and you want to be ready for it.
Also around here most overyone uses 1/2" pex tubing placed 12" OC with pretty much equal loops of about 250-300 feet. Buy 1' foot of 1/2" pex per square foot of foundation. My shop was build on grade ans does not have any rebar in it, so I put some masons "woven wire" (6" x 6" wire) down there to attach the tubing to. Worked great. Don't overthink the radaint floor heat as you are essentially heating a rock using warm water just like the Romans did. It is a rock and mine is about 42 tons of thermal mass concrete and will average it out.
My shop just uses hot water from my house propane fired Baxi boiler for the heat that is on it own zone. 3/4" pex to and from to my shop in underground PVC. I converted the whole house to radiant heat on demand while I was building the shop. Money well spent. I didn't use any antifreeze in my radiant set up, but I would have to lose power for a long time in real cold weather for that to be a problem. I could run the whole thing off my little generator if I had to.
My shop is 6" of 4000 psi concrete. Where my 2 lift posts go, I exchanged the 2" of foam for an additional 2" of concrete with no pex for 36" all around each post location on advice from BendPak. My concrete guy was very good and the top foundation elevaton was within 1/4" from high to low. I was impressed.
My buddy is one of the local bulding inspectors and he was a great asset in giving me good advice on the SIPs and the radiant floor heat. His advice was to buy the good panels, run the wiring in conduit surface mounted, and buy the Upanor O2 barrier pex tubing even though it costs a little more. My heating guy and the electrician also went out of their way to do good quality work.
Find somebody like that near you. Every place is a little different. If your SIPs guy wants to show off your building for future customers, use that also to your advantage. It gets cold here in Maine, but it is probably colder where you live and you want to be ready for it.
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Thanks Randy.
I think the heated floor with pex is a reasonable approach. I am already running water to the garage and am intending a hot water heater also. Is it possible to combine the two? I think I would prefer antifreeze but I'm wishy washy on it. If I could save myself an extra hot water tank it might be worth it.
Do you find you ever want more 'on demand' heat? Any idea how in floor heat compares cost wise to the other options?
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I think the heated floor with pex is a reasonable approach. I am already running water to the garage and am intending a hot water heater also. Is it possible to combine the two? I think I would prefer antifreeze but I'm wishy washy on it. If I could save myself an extra hot water tank it might be worth it.
Do you find you ever want more 'on demand' heat? Any idea how in floor heat compares cost wise to the other options?
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Randy in Maine
Well-known member
I also have domestic hot and cold water out to the shop but my little boiler does both at the same time. I have never run out of hot water but I never run the dishwasher while I am in the shower. I don't have any kids either.
I figure the radiant floor heat have me about 1/3 in heating costs and I just find it a lot more comfortable when I have warm feet. With radiant floor heat you just set it to one temp and leave it.
I figure the radiant floor heat have me about 1/3 in heating costs and I just find it a lot more comfortable when I have warm feet. With radiant floor heat you just set it to one temp and leave it.
My studio is all SIP's (walls and roof deck) -- pipe for the horizontal ties . makes for a very tight building and I like the tall ceilings.
Building with stick and foam is greta also -- my last couple of houses are foamed. Don't mess around with vents or vapor barriers -- spray the roof and be done with all the problems.
Any tight building needs ventilation -- this is not difficult.
Building with stick and foam is greta also -- my last couple of houses are foamed. Don't mess around with vents or vapor barriers -- spray the roof and be done with all the problems.
Any tight building needs ventilation -- this is not difficult.
rancherbill
Well-known member
Water in the garage is going to be expensive, you'll have to put the line 5' into the ground and the sewer will be even deeper, or you'll have to build a dry pit / well. That's a lot of excavating.
If you go with infloor heating it MUST have antifreeze. Some event will occur and you don't want to damage the concrete from freezing. If your regular water heater burst you just have a mess to clean up not replacing the concrete.
rancherbill
Well-known member
It's great that the sewer is already there. I wouldn't rely on heat traces alone.
Check out heat boxes. Basically you build a three sided box out of foam that goes on top of the water line. It provides insulation and thus more freezing resistance.
On page three they have a frost box with tape.
http://devi.danfoss.com/NR/rdonlyres/6B5C1FFF-664A-495C-B6DD-540E46523C43/0/Pipe_tracing_applikation_sheet_print.pdf
I have floor drains in my garage, and I built a dry well and run the water from the cars to it. It protected it with foam. It is about 4' deep with no snow cover and it has not frozen yet.
If it is legal you could hook your floor drains to the sewer. Have you checked yet?
Check out heat boxes. Basically you build a three sided box out of foam that goes on top of the water line. It provides insulation and thus more freezing resistance.
On page three they have a frost box with tape.
http://devi.danfoss.com/NR/rdonlyres/6B5C1FFF-664A-495C-B6DD-540E46523C43/0/Pipe_tracing_applikation_sheet_print.pdf
I have floor drains in my garage, and I built a dry well and run the water from the cars to it. It protected it with foam. It is about 4' deep with no snow cover and it has not frozen yet.
If it is legal you could hook your floor drains to the sewer. Have you checked yet?
I contacted this company in Ontario. This is what they do.
http://www.heatline.com/paladin.htm
It's $340 for a 30 foot line that is ready to put in the ground at any depth. It is controlled via thermostat. You just add insulation. My plan is to put it just below my frost wall at 4'.
The city is fine with me putting a floor drain directly to the sewer. That is my preferred solution so I'm glad they were good with it.
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http://www.heatline.com/paladin.htm
It's $340 for a 30 foot line that is ready to put in the ground at any depth. It is controlled via thermostat. You just add insulation. My plan is to put it just below my frost wall at 4'.
The city is fine with me putting a floor drain directly to the sewer. That is my preferred solution so I'm glad they were good with it.
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Well I've got my first quote for SIPs. It has been interesting learning about this approach to building. I won't name the company who provided this quote as I think that is somewhat disingenuous however if you are local and want their name, just PM me
First off the city says I need a frost wall of 4' on top of a footing. I still think this can be challenged but nonetheless this company makes their panels with MGO board. This is a type of cement called magnesium oxide. As such the panels can be used above and below grade. They also have an OSB version for above grade. The OSB likely still needs drywall to look nice, while the MGO is ready for paint, or can be left as is.
The frost walls are 6.5" thick and R30. They are 4' tall.
The wall panels come in prefab sizes of 6.5" thick for walls, with an R22 rating. They are 4'x9' but I think they have several different sizes prefab.
The roof panels are 10.5" thick and R40. They are 4'x12'. The roof is constructed using three beams. One ridge beam and one part way down each roof slope. Those beams require structural supports on each side. I think I could effectively argue for an engineered slab with pilings under each support and axe the frst wall entirely.
The quote is as follows (all in Canadian Dollars)
Frost wall: $5890
Exterior Walls: $11350
Roof: $14726
Engineering and Drawing: 1900
TOTAL: $33867 +GST
Each section includes all lumber, fasteners, beams, adhesive, and cut to fit its needed place. So the resulting pieces are like lego... you just put them together according to instructions.
Obviously I could save almost $6000 by getting rid of the frost wall requirement. As I said before, concrete will be easy for me.
By going with OSB I can reduce another $4000.
I'm going to run a comparison against my old budget to see how this stacks up.
My guess is this approach is 10 to 15% higher
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First off the city says I need a frost wall of 4' on top of a footing. I still think this can be challenged but nonetheless this company makes their panels with MGO board. This is a type of cement called magnesium oxide. As such the panels can be used above and below grade. They also have an OSB version for above grade. The OSB likely still needs drywall to look nice, while the MGO is ready for paint, or can be left as is.
The frost walls are 6.5" thick and R30. They are 4' tall.
The wall panels come in prefab sizes of 6.5" thick for walls, with an R22 rating. They are 4'x9' but I think they have several different sizes prefab.
The roof panels are 10.5" thick and R40. They are 4'x12'. The roof is constructed using three beams. One ridge beam and one part way down each roof slope. Those beams require structural supports on each side. I think I could effectively argue for an engineered slab with pilings under each support and axe the frst wall entirely.
The quote is as follows (all in Canadian Dollars)
Frost wall: $5890
Exterior Walls: $11350
Roof: $14726
Engineering and Drawing: 1900
TOTAL: $33867 +GST
Each section includes all lumber, fasteners, beams, adhesive, and cut to fit its needed place. So the resulting pieces are like lego... you just put them together according to instructions.
Obviously I could save almost $6000 by getting rid of the frost wall requirement. As I said before, concrete will be easy for me.
By going with OSB I can reduce another $4000.
I'm going to run a comparison against my old budget to see how this stacks up.
My guess is this approach is 10 to 15% higher
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rancherbill
Well-known member
Does the engineering include an Alberta P. Eng drawing for the foundation? Building inspectors usually require them for any non-concrete foundation.
Good question. That is one I will ask them.
I also want to get clear on the need for a frost wall. I don't see how increasing the square footage of a structure creates the need for a frost wall. I think it should have to more to do with the weight of the structure and the load points.
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I also want to get clear on the need for a frost wall. I don't see how increasing the square footage of a structure creates the need for a frost wall. I think it should have to more to do with the weight of the structure and the load points.
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Randy in Maine
Well-known member
The purpose of the frost wall on footer is to provide for good structural stability for watever type of garage you decide to build. I think my stemwalls are 8" thick and site on a footer that is about 8" thick and 16" wide. The local code guy will know just what is required. Trust his advice since he sees it done every day.
Also this is the time to descide just how many conduit pipes that will need to run under the fronts walls to provide for hot/cold domestic water, electricty, phone and computer lines, and heating water & sewer if you are going that way.
Whatever kind of construction you eventually decide to do will pretty much all be built on the same foundation.
Around here we don't run heating cable aong the water lines. If they are 4' below grade, just insulate the top and sides of them using 2" rigid foam and they never freeze.
Also this is the time to descide just how many conduit pipes that will need to run under the fronts walls to provide for hot/cold domestic water, electricty, phone and computer lines, and heating water & sewer if you are going that way.
Whatever kind of construction you eventually decide to do will pretty much all be built on the same foundation.
Around here we don't run heating cable aong the water lines. If they are 4' below grade, just insulate the top and sides of them using 2" rigid foam and they never freeze.
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The numbers say our ground freezes down to 7'. The water and sewer lines to the house are at 8'. So the rules state anything less than 8' need to be heated.
I seriously doubt it freezes that deep but maybe it did once upon a time.
Explain to me why square footage determines the need for a frost wall. I get why they do it, but why is 55m^2 the threshold?
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I seriously doubt it freezes that deep but maybe it did once upon a time.
Explain to me why square footage determines the need for a frost wall. I get why they do it, but why is 55m^2 the threshold?
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Randy in Maine
Well-known member
Sometimes there are stricter codes for larger building. I would guess that the cutoff is 55 square meters.
That depth to freeze is based on local conditons. I knew it got cold up there, but damn that is cold.
That depth to freeze is based on local conditons. I knew it got cold up there, but damn that is cold.
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dirttracker18
Well-known member
Keep in mind that is a worse case scenario. You don't want your water lines just below average frost depth only to have a bad year (no snow and very cold) and have them freeze.
Mine come out of my basement at the floor and continue at that depth until they are under the slab. They then turn 90* up and into my garage. I also carefully backfilled just up a flat surface at the depth of the line and placed 2" X 2' X 8' foam over top from the house to the 90* bend.
I have never had an issue with freezing and I have had very cold winters with no snow since the build.
I've confirmed that the engineer is a P.Eng and the drawings are stamped. I've asked them if they could also design the foundation and slab - they said yes. I'm going to meet with them next week to discuss with the engineer.
I seem to be going down this SIPs road almost entirely by accident.... funny where GJ can take you..
If you want an almost guaranteed no possible problems insulation then Foamglas. http://www.foamglas.com/ It is however expensive.
Both EPS and XPS foam will work for underslab, and both can be problematic. Basically the cheap stuff can be a problem and the good stuff can do well. XPS is generally considered better because it typically can resist water intrusion into itself a better than EPS does.
Regardless you need a compression rating that is above your soil conditions, and it needs to be installed over a capillary break (typically 4" of 3/4" compacted gravel with fines). You should also install a vapor barrier between the insulation and the slab.
I've confirmed that the engineer is a P.Eng and the drawings are stamped. I've asked them if they could also design the foundation and slab - they said yes. I'm going to meet with them next week to discuss with the engineer.
I seem to be going down this SIPs road almost entirely by accident.... funny where GJ can take you..
You may also want to consider a precast foundation system like superior walls. http://www.superiorwalls.com