Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Cutting groves in cement

hr Member Posts: 6,106
I'd be interested to know the hours involved and the problems encountered.

Does the old slab have insulation under or around it?

I thought this was a clever tool design when we watched it in Denver. Tell us more.

hot rod

<A HREF="http://www.heatinghelp.com/getListed.cfm?id=144&Step=30">To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"</A>


  • John Felciano
    John Felciano Member Posts: 411
    Cutting concrete

    If anyone was at the RPA radfeast trade show in Colorado last April they may have saw the concrete grove cutting saws by US Saws. I'm currently working with them on a project to cut the cement floors and install radiant tubing in a house.

    The house was built in the 1950's and originally had radiant floor heat (welded stell)which must have leaked and was abandened.Electric T ray was installed at some point and the new owner wanted to go back to radiant.

    After a few inital problems the groving has been going well.A large angle grinder mounted on a special frame makes the radius cuts and a larger wheel mounted saw makes the straight cuts.Both cutters leave a small portion of cement that is easily cleaned out with a screwdriver leaving a nice 5/8" wide grove in the cement.A high powered vacume makes the whole cutting process almost completely dust free.
  • John Felciano
    John Felciano Member Posts: 411
    Crete cutter

    We are keeping track of the amount of time on the cuts,but so far it's been a learning curve and some experamental stuff.Will keep you posted.

    Looks like about 2 minutes per radius cut,we've been trying different blades. and about 4' per minute with the double bladed straight cuts.

    There is some kinda insulation under the slab as it did have radiant.Not entirely sure about the perimiter.
  • Bill_14
    Bill_14 Member Posts: 345
    post-tensioned reinforced concrete

    What if you run into post-tensioned reinforced concrete? How deep is your groove?

    Bill Russell
  • John Felciano
    John Felciano Member Posts: 411
    Cutting concrete

    The cuts are about an inch deep and 5/8" wide.The tubing fits in fairly snug and has to be tapped in with a rubber mallet.We are planning on useing pex-al-pex as I'm afraid the barrier,on regular he-pex, will get scratched off against the concrete pushing it in.

    The biggest challange so far has been with the radius cutter.The blades are custome bent like a bowl to be able to make a circular cut.It's been a bit of a challange finding the right blade and angle that will cut without binding.

    We also found that we could get 12" and 10" spacing by making the radius more than 180* and cutting the straigh cuts closer together haven't tried anything tighter than 10" but I think it might work as close as 8".

    We have been kinda beta testing the tool out so it's been a learning curve for us all.
  • John Felciano
    John Felciano Member Posts: 411
    Setting the tube

    So what do you guys think. Would it be benificial to put some kinda silicone or grout under the tube before pressing it in?The tube fits pretty snug so it wouldn't have to be there to hold it, but more for heat transfer.

    I do plan on cementing/grouting the 1/2" or so over the tube making it flush with the floor.

    If anyone is interested US Saws will be at the RPA Radfeast East this October in DC
  • hr
    hr Member Posts: 6,106
    I think

    if the tube is staying down in the groove ok, I would use a cement grout type product. Better heat conduction and a lot less $$ and mess.

    I just patched a slab "mistake" and used this non shrink product. Went in smoothly and set up real fast. It seems to be a bit thicker, or something, than basic sand mix cement. It was easy to trowel even with the old slab. Much easier than silicone, I suspect :)

    What will the floor covering be?

    hot rod

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • John Felciano
    John Felciano Member Posts: 411

    For the most part a floating wood like Purgo.Some ceramic tile.

    So you think a thin layer of grout before the tube is set in for heat transfer?The bottom of the grooves are a little jagged where the remaining center section was chipped out,so it may protect the tube as well.How fast does it set up?Would there be time to get the tubing in?

    I like the looks of that (cw100) I'll have to check my local builders supply to see if they carry it.
  • hr
    hr Member Posts: 6,106
    You might

    try getting a putty knife the width of the groove, mix the grout wet, smear a bottom layer, insert the pipe and smear the top layer with a float to ooze it around the tube.

    As long as the tube is fairly tight in the groove I think this would work.

    Find a concrete supply speciality shop and ask if they have products with different set times. This stuff goes off fairly quickly, I'll bet there are other blends.

    This CW brand, is actually a local company, Carter Waters. Any concrete supplier should have a similar product.

    I like the non shrink part of this mix. this will assure the "patch" stays level with the rest of the floor for good conductive transfer to the floating floor.

    I prefer the smell of cement to that of silicone :)

    Again, let us know. I'm looking at a potential "groove job" on Saturday. Hurry up and let me know how yours works out :)

    hot rod

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Jon_10
    Jon_10 Member Posts: 47

    Judging by the label on the bag of grout hotrod had, it is the same as PourRok (sp). It is a specialty cement, made up in small batches and poured in the cavity. It is a non shink type and working time is about 15 minutes. It should work perfectly for your application, 1st. pour in bottom of groove, 2nd. on the tubing. Works great for setting toilets on concrete floors, set toilet in place, outline with chalk, remove toilet, put light coat on grease on toilet perimeter surface, pour mixture on chalkline as req'd, set toilet with seal and wipe off excess around perimeter of toilet. Toilet will never rock again.
  • John Felciano
    John Felciano Member Posts: 411
    More on the Groovy job

    The job has been moving along slowly with the usual construction delays.We got back in there the other day and started in on another room.

    The concrete is VERY hard from the 1950's and cutting is a bit slower than expected.We got most of the bugs worked out with the radius cutter and that is working great.The straight cutting was a little slower than expected due to the hardness on the old concrete so we switched to wet cutting to speed things up.It's a bit messy but cuts a bit faster.I'm hoping to try the saw out on some not so old concrete as the manufacturer says it will cut alot faster.

    Chipping the waste from the grooves went fast with a air chissel and cleaned up very nicely.The tubing (pex-al-pex) went in a bit harder than I would like but adding a shim and widening the groove will take care of that on the next room.

    We filled the space above the tube with a commercial non shrinking floor leveler.Mixed it up like a thin milkshake and just poured it in.It self levels and went in quickly.

    All in all it's going pretty well for a beta testing job.I'd say once all the bugs are straightened out the system will be competitive with doing a Quicktrack/Climate panel system but without having to raise the floor.

    If anyone is interested in more info on the job, US Saws will be at the RPA Radfeast East tradeshow. I'll also be at the round table discussion with a bunch of pics and info on the job.
  • JOHN_103
    JOHN_103 Member Posts: 54

    have you tried using the acp panels made by stadler ?
    if so which do you prefer? I think they would add about
    1/2" to the job . not sure if it would be easy enough to install over concrete floor . any thoughts
  • John Felciano
    John Felciano Member Posts: 411
    Climate Panel

    We've used loads of climate panel and have in fact fastened them to concrete floors,as a matter of fact my radiantly heated showroom was done that way.Attaching them to the floors is the problem.We've used trakfast guns and shot them in the past.Works O.K. but then there is the floor height issue.On this house raising the floors even 1/2" would have cost thousands in additional costs of raising all the exterior doors (6) which are flush to the floor as well as all the other issues that go along with the extra floor height.

    This is another option.I'm very excited about this system as it has lots of potential.I see lots of cold basements and garges where this system will work perfectly.
  • Bob Harper
    Bob Harper Member Posts: 1,028
    cutting radius grooves in concrete

    Check out a stone fabrication supply house like Braxton Bragg or Eastern Supply for diamond router bits. Make up a jig for whatever radius you need. Using a 3 hp plunge router, make multiple passes and use good dust control and respiratory protection along with the rest of your PPE.
  • John Felciano
    John Felciano Member Posts: 411

    The grinder making the radius cuts as well as the straight cutter are almost completely dust free.The have shrouds and attach to a awesome two stage vacume that does a very impressive job of keeping things dust free.

    Resperators and the rest of the safety equipment is still needed but there is very little mess.
This discussion has been closed.