Replacing a downstairs Loo.

[Jack44]

First post on here so hope this is in the right place. Replacing a downstairs loo on a concrete floor. Not got it yet, on order arriving next week. If the tech drawings are correct the new fixing holes will have 1mm between their outside diameters and the original (old fixing holes, so a sort of figure 8 . Q. ...Has anybody used Rawplugs R-Kem anchor bond? If I plug the old hole with R-Kem will this prevent the drill running off into the old hole and prevent the new fixing breaking into the old hole when tightened up. Both holes 14mm, I intend pilot drilling first with a 6mm masonary then a 10mm before opening up to 14mm. Which I am hoping will acheive a clean final 14mm hole. I suspect a strong mortar mix or even neat cement in the old hole could allow a 14mm drill to run off, plus it will take a day or two to reach full strength but in reviews I'm reading R-Kem is likely to be much better for this kind of application although it's not really it's intended use.

 

[Wayners]

I'd drill hole bigger then push a raw plug in the resin at the correct location. Maybe make a template up to get it in the correct location.

I've never drilled bolt resin and wonder If the drill will wander off in the softer concrete. That resin is very hard.

 

[tell80]

Ask mods to move your thread to plumbing.

As for your question - do nothing until the new WC arrives.
Typically, the WC pan becomes a template for fixing to the floor - not the drawing.
Set the pan (in a slightly new position, perhaps) & dry fit all pipe and fittings - check-mark all connections for re-assembling. Mark the position of the pan on the floor.
When satisfied with everything then:
mark the floor down thro one of the fixing holes,& move the pan to the side.
Drill & plug the mark.
Lightly screw down the pan. SF do packs for fixing pans to floors.
Swivel the pan into position.
Mark an opposite hole & do the same again.

 

[Jack44]

Yes thanks for the advise I have installed loos before but it's always good to get second opinions/advise so thanks for taking that trouble. I'm just trying to plan ahead. I also can't be sure if the tech drawings will be totally accurate as I expect I shouldn't be surprised to find +/- a milimeter or two with a ceramic casting. If so with a bit of luck it may be plus in my favour. Also because of pipes exiting the wall coupled with the Soil pipe position (it's a semi back to wall with a tricky side entry) I'm expecting to not have the luxury of selecting a slightly different position but then, with a bit more luck, I may be able to pinch a mm or two which may be enough. After Wayners reply (NB I don't want to drill the resin just use it to fill the old hole) I've never used anchor resin before and just wondered if it really is as hard as it is claimed to be. So now that Wayners has confirmed it is actually that hard I now plan to open up the new hole even more gradually than previously stated and before plugging the old hole with the R-kem. Drilling 6mm - 8mm -10mm - 12mm - 14mm. That way the possibility of the 14mm breaking into the old hole will be kept to the minimum but if it does eventually break into the old hole the new hole should still retain its centre. Plus those nylon floor fixings are fairly numpty proof anyway with about 10mm lateral variance built in. I'll make a judgement if the new hole needs to be bigger as Wayners suggests once I get it to 14mm but if it has retained all or most of its circumferance intact I'll do as suggested and fill the old hole with the resin after drilling and if the material separating the holes has broken down allowing the resin to flood through into the new hole{s} with the supplied plugs in place the fix should be good enough once the R-kem has set and it is harder than the concrete. Have I missed something? Any further advise/suggestions would be appreciated.

How do I request this be moved to plumbing as you advise