Grout technique help...

My experience of grouting has not been good. The usual advice in fine in theory ;-) Most folks say my tiling looks good (genuinely) but it is not a professional standard, especially when viewed in directional lighting.

I would welcome some advice that specifically addresses the following issues. General advice has not really helped.

I tended to wipe off with a sponge too early (yes, I did it diagonally) resulting in a bumpy looking untidy grout line. This was not helped by the cheap tiles I used (false economy) which had no glaze on the "sides" so you had to grout onto the bevelled part, which was very shallow meaning that any unevenness was exaggerated. Professionals can get good result with these cheap tiles somehow !

Why did I wipe off too early ? Because if I left it as long as suggested, it was impossible to easily remove the excess from the tiles.

I was going to use a dowel along the grout lines as is sometimes suggested, but the tile arrises were too undefined resulting in the unglazed edges grinning through if I did this.

My mistakes I think:

1. Poor float technique resulting in too much grout left on the tiles. You should squeegee most of it off.
2. Grout too thin, should be more like paste than whipped cream, so it is tougher sooner in the process so wiping off earlier does not damage it.
3. I did not "compress" the grout enough.
4. Cheap tiles with a poorly defined unglazed edge and red rather than white biscuit.
5. I think the pros just use the float with constant pressure to get a slightly recessed grout line, don't leave much on the tiles, and wipe off at just the right moment. I other words, similar to plastering, technique is everything.

The result looks OK in daylight, but with the lights at a shallow angle to the walls, it does not make me pleased ! Grout looks slightly uneven and slightly rides up the bevels in places. I used grout sealant after, and it appears perfectly watertight around the shower though.

One day I will regrout the bathroom !

Simon.

I sponge off the tiles when the grout is wet with a scouring sponge and a lot of water.

that gets 99% of it. The tiles dry cloudy with the 1%

That gets removed with more water and descaler fkluids. Anything up to brick acid!!

That does dissolve the grout by a fraction of a mm where its wanted, too. but there is plenty left.. :-)

sm_jamieson wibbled on Wednesday 14 July 2010 09:29

Hi Simon,

A lot of the "pro" wall tiling I've seen has left me thinking mine is at least better than 30% of the professional stuff out there:

(Last house) - they "forgot" to use tile spacers so the tiles abutted and the grout was hairline thick - and fell out.

(More than one restaurant) - massive format marble tiles with no bevel with some laid badly so corners sticking up - looks horrible which is why I'll never use a square edged (non bevel) tile.

I'm using these:

Those you can just see on the coloured samples have a wavy surface texture and slightly wibbly edges and a bevel. The glaze goes about 1/3 the way down the edges.

They are *very* forgiving of not being laid dead level or with perfect spacing (though it is essential to get them in straight rows and columns - but minor spacing adjustments don't shout out at you).

To get a nice grout line, 1-2mm inter-tile spacing seems to be about right with those, plus the grout should be washed out about 1mm below the top surface.

This means using a sponge quite generously after 15 minutes with fairly little chance of being able to over rub the grout.

It's the 2nd cleanup that's a little fiddly - cleaning the surface is fine - good rub with paper does that. It's rubbing the bevels clean that's tedious.

I'll try some variations today like a damp wash after an hour, use a tile "scourer" (open mesh non abrasive pad - I have a fine grade one) and a dry rub sooner rather than later and see if any of those work more efficiently.

I went by the grout data sheet that suggested 10-20 minutes, but I do have a fairly fast grout (don't know if it's faster than normal or not).

I had the same problem with floor tiles. The bevel doesn't have a lot of glaze and I laid them with slightly too much gap - the pro tiler who did my slate floor said they were perfectly passable but he'd have used a smaller gap and I agree with him. He did praise the wall tiles I'd done though :)

The floor grout got a bit grubby (didn't have any sealant) and because it's slightly low (odd dark line of tile biscuit showing), I'm going to over grout it with 0.5mm and seal immediately to freshen it up.

When he did the slate, he used small gaps (2-3mm) and wiped off within 10 minutes IIRC. I think small gaps make life easier.

I agree - I tried harder at that phase and I did have less crap to get off the face.

Mine was quite pasty - but me being me, I used the kitchen scales to get a

I'm very concious if that in the shower area - don;t want that leaking...

Yes - good edge glazing certainly helps.

I was able to control the general grout line quite well - the Mapei stuff goes pretty solid after 20 mins in, but the surface responds to a damp sponge and comes off very gradually and gracefully. It's what's left (or gets put in at this stage) into the bevels and the lumpy bumpy shallows that I haven't fully cracked yet.

Don't envy you that job...

Cheers,

Tim

Well there are "pros" and pros. I was looking at the walls of the work toilets. Loads of lovely neat grout on tiles about 8" horiz and 3" vert.

Well so far its down to having tiles with edge glaze and a recessed finish. Its annoying that if I had have used tiles suitable for doing this, I would have got a better result. The kitchen is next, and I may be using those trendy "brick" tiles with a bevelled surface, which may be fun. They will have glazed edges and I will probably use a dowel to level the grout using the tile edges as a guide. That cannot go wrong !

Its often the case that pro's can get a good result with poorer materials !

I like the idea of grouting using a sealant gun, although I suspect the grout may then have to be a little too liquid.

Simon.

FWIW I spread the grout with a 4" metal scraper. Then I run the ball end of a glass cutter over the joints, dipping it in water every few tiles (works better than a dowel for me). What's left on the tiles I leave to dry i.e. I don't do the sponge bit at all. The scraper removes the grout from the faces easily when dry and I don't need to touch the grout lines. The only downside of not using the sponge is more powder to sweep up at the end. That's with standard grout BTW....

stuart noble wibbled on Wednesday 14 July 2010 10:52

Interesting totally different method :)

Yeh, some modified grouts would be harder to remove at the end. Worth checking before you start. I suspect I will use that sort of method on my next tiling job though.

Have you considered using a sealant gun, which would fit fine with your method, and nothing on the tile surface ? Simon.

Simon.

And may not work with all grouts. First lot of tiling I did, the film would wipe off dead easy when dry, either with a dry or damp cloth. The lot in the bathroom with a, probably cement based, waterproof grout doesn't shift at all easy and as for any small lumpy bits left on the tile faces. B-( Angle grinder comes to mind...

can't imagine a sealant gun approach would work.... I imagine the gun applied would not achieve a full depth and adhesion to the bottom and tile edges whilst simultaneously leaving a "perfect" visual result...

I've never really had an issue with grouting tho never done *really* bumpy tiles... I haven't used modified grout either

- just ready mixed of one sort or another (all claim to be waterproof). Slather on, push in well with tool of choice, dowel the gaps with wooden/plastic implement NOT a pencil with printed sides!! (Scrwfix do a good round print free pencil FOC;>)), leave to go off, diagonal sponge action to remove excess, leave again, scrub with harder side of sponge to clear films etc.

Cheers Jim K

The idea would be not to apply a "bead" and leave it to cure, just use the gun to get enough into / onto the gap and still compress it in with a float and finish with a dowel if required. You would just end up with most of the tile completely clean ! Simon.

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This technique (metal scraper) works best for me too although it might be a bit slower than the squeegee method. The metal scraper seems to drive the grout deeper into the gaps - avoiding 'pin-holing' especially with less stiff grouts.

Wickes sell a handy little tool for finishing the grout lines:

sm_jamieson wibbled on Wednesday 14 July 2010 12:07

I *might* have cracked it (good feeling, wait 'til later to be sure).

This time I sponged the faces after 20 mins.

Then immediately I went over with an open mesh "scourer" on a backboard+handle (I can't find an internet picture - might do later). This seemed to recess the grout quite nicely and clean the faces.

Then with clean water, I sponged again to re-smooth the grout (the "scourer" leaves a slightly rough finish). Then more clean water and a light wipe with the sponge.

Then rinsed the bath with loads of fresh water (dried grout + acrylic isn't the best combination - and I always have an old blanket in the bath to stand on too).

Just waiting for the neighbouring tiles to dry off a bit then the next wall...

Cicero wibbled on Wednesday 14 July 2010 13:02

Haven't had the pin holing problem with a rubber float. I hand mix the grout with a wooden spoon which might minimise entrapped air. OK, I get the odd pin hole (maybe 2-3 per kg mix) - but they seem to fill in during the washing phase.

Dave Liquorice wibbled on Wednesday 14 July 2010 12:21

This stuff seems to dry wipe within 6 hours OK. After 24 hours you're totally buggered though, it's iron.

Tim Watts wibbled on Wednesday 14 July 2010 13:56

I'll just add, I've had this scourer with 3 pads of varying coarseness (I used the finest) all the time but I've been too scared to use it as I thought at first it might be too aggressive. Apparantly not...

er...I doubt one could use a float/squegee without spreading onto faces of tiles?

to the point where you may as well slap it all over 'em like everyone else does! Particularly with the quicker set stuff:- how much faffing about time is there to be tickling around grout lines only to still end up with the smeary film to deal with after??

Spose it would depend on the size of the tiles i.e. bigger ones may give you most to gain but I can't see how it can be worth the extra agro.

Cheers Jim K

You know those trendy brick style tiles, where the surface has a large bevel about 15mm from the edge (like a bevelled edge mirror), where moving a float across the overall surface gets you nowhere near the grout gaps ? I think it would be tricky using a float to get the grout in, since you could not just wipe the grout diagonally across the surface like usual. The sealant gun method may help a lot in that situation. Simon.

tell me.

sponge in hydrochloric acid finally worked. Dont use on marble tho :-)

A rubber sponge (not PU foam), couple of quid from Axmionster, is well worth it as a rubber-offer.