Pex in floor (multiple pours)

[kert]

Have a contractor bidding my 30x60 slab and wants to do it in 3 sections. Is there any problem with multiple pours over PEX? The PEX could probably be laid out to minimize the number of crossings, but should I be concerned about the tubing failing at the joints? I suppose I cold even put in 3 manifolds so that the lines don't cross the joints.

 

[pstnbly]

The pex should be sleeved in scd 40 pvc conduit at the joint between pours.

 

[kert]

The pex should be sleeved in scd 40 pvc conduit at the joint between pours.

Good answer. Thanks.

 

[stingry]

personally I would find a contractor that would do it in one pour, thus eliminating any joints to cross with the PEX. 30 x 60 is an easy pour for a contractor that has the right equipment.

Cheers
Steve

 

[cj7365]

Eliminate this thread by finding a contractor that will do it in one pour, there must be an inexpierence reason why he needs to do it in separate pours, Whats his reasoning for doing it in separate pours? if he can't handle it in one pour find a contractor that can.

30x50 slab with 2 each 16x20 driveways, ONE pour, 6 hrs

 

[Aaron Franck]

I agree, one pour should be easy enough. I, and ten friends (two finishers) poured my 50' x 70' 6" thick over pex tubing, no problems.


Aaron

 

[maxspeed96ct]

Eliminate this thread by finding a contractor that will do it in one pour, there must be an inexpierence reason why he needs to do it in separate pours, Whats his reasoning for doing it in separate pours? if he can't handle it in one pour find a contractor that can.

30x50 slab with 2 each 16x20 driveways, ONE pour, 6 hrs

have any pics of your tubing layout and how you attached it before the pour?

I've seen a 6" slab done in two pours, first 4" was done. Then after tubing and barrier was attached the last 2" were laid down..

Is that a incorrect method ?

 

[Highbeam]

have any pics of your tubing layout and how you attached it before the pour?

I've seen a 6" slab done in two pours, first 4" was done. Then after tubing and barrier was attached the last 2" were laid down..

Is that a incorrect method ?

Yes, that's retarded. The top thin slab is only 2" and could suffer from bonding problems. Would be unfortunate to have that spall off.

My 30x60 was 5" thick and poured in one day by only about 5 guys. Everybody went home after the first float and the main man finisher stayed until dark to run the power trowel.

Here's my pex all ready for pour. Best photo I have on this machine. I took lots more photos to help with locating it in the future.

 

[kert]

Problem solved. The contractor asking was $4-5k more than the first bid who has experience with in-floor heat and generally impressed me more.

The contractor who was asking said he wouldn't need as much help to do smaller pours, so it would save me money. That didn't quite make sense to me.

 

[maxspeed96ct]

Yes, that's retarded. The top thin slab is only 2" and could suffer from bonding problems. Would be unfortunate to have that spall off.

My 30x60 was 5" thick and poured in one day by only about 5 guys. Everybody went home after the first float and the main man finisher stayed until dark to run the power trowel.

Here's my pex all ready for pour. Best photo I have on this machine. I took lots more photos to help with locating it in the future.

Sorry for the noob question, but how did you lay the pex in one 5" pour, I thought it had to be done it at least two layers ?

 

[stingry]

Sorry for the noob question, but how did you lay the pex in one 5" pour, I thought it had to be done it at least two layers ?

insulation, PEX,wire mesh, pour concrete, DONE. or some prefer: insulation, mesh or rebar, PEX then pour cement. If you want the PEX more towards the center, you can stand rebar or mesh on rebar stands, tie PEX to mesh or rebar and then pour.


Cheers
Steve

 

[Highbeam]

Sorry for the noob question, but how did you lay the pex in one 5" pour, I thought it had to be done it at least two layers ?

Take a look at my photo. The next morning, we poured the mud. Full depth. There is no requirement that the tubes be centered in the slab.

You set up the tubes, VB, insulation, reinforcement, in advance and then pour.

I actually prefer the tubes lower in the mud so that they are less likely to be felt as hot spots and less likely to be hit when sawcutting or installing anchors.

 

[maxspeed96ct]

Take a look at my photo. The next morning, we poured the mud. Full depth. There is no requirement that the tubes be centered in the slab.

You set up the tubes, VB, insulation, reinforcement, in advance and then pour.

I actually prefer the tubes lower in the mud so that they are less likely to be felt as hot spots and less likely to be hit when sawcutting or installing anchors.

gottchya, I always thought you wanted the tubes towards the top ...

 

[Ken Greene]

Control joints cut into the floor to help with cracking, will make joints in the floor. cracking in normal for concrete. control joints try to make the crack form where YOU want them not where they want to be. Plan out your tubing and control joint to limit the crossings. but in the thousands of yards of concrete poured we have never had any issues.

 

[BadgerBoilerMN]

We design and install radiant floor heating systems. All of our residential pours are done at once. There is no reason to protect the PEX at control joints (hand or saw cut). There is generally no reason to suspend the PEX in the slab in the typical non-commercial building.

Tube depth, pattern, spacing, size, length and flow are determined by the intended use and the specific heat load of the structure.

We perform proper heat loads and CAD drawing for owners, contractors and mechanical engineers all over N. America.

One more item: wire placed at the bottom of the slab serves no useful purpose. We staple tube to XPS at 4 times the speed of tied tube.