Grouting a stone patio

[Bitpipe]

We have just had our paving laid around the perimeter of the house. Now need to grout it!

 

I got a great price on 600mm x 900mm x 20mm smooth platinum grey sandstone slabs (£30/sqm) and the landscaper laid about 100m2 of them on a sand & cement mix (with SBR). Opted against brick bond for a more contemporary look with 5mm gaps and while it was more fiddly for him it looks great.

 

Standard paving grout (such as Easy joint) is intentionally porous but the landscaper is concerned that because the slabs are so smooth underneath, any water ingress and frost may loosen the slabs over time so he's suggesting a more impermeable grout such as BAL widejoint - this is stated as suitable for external use (such as pools) even more so if you use their GT1 admix.

 

I've decided to do this part myself, any tips or advice? Not sure if this is best done by just ramming it into the gaps or to use a applicator gun.

 

---

 

About the paving...  we laid them flush with the house entrances and maintained a 100mm separation from the render horizontally and 200mm vertically. Once the channels are cleaned of muck, i'm applying 200mm of grey Ubilflex to the exposed external EPS and will then fill the bottom 100mm with a decorative stone to act as a french drain. Because we have a basement, there is a 1m perimeter of clean stone cobbles as backfill with a land drain at the foot of the basement so it's very free draining. Patio also falls away from house in all directions.  BC and the render firm approved this as acceptable.

 

To tidy the EPS plinth prior to paving, I applied an additional 25mm EPS to 200mm depth all around, lapping the DPM from the frame down under the new EPS. This new EPS also covered any exposed timber where the outer leaf of the frame slightly overhung the original basement EPS.

 

Where we paved up to doors, the DPM went over the top of the stone and has been trimmed back, will run some sealant along those edges to keep water out.

 

Garden will be graded and laid to lawn in a few weeks, then a deep breath and we start to plan the front of the house - just getting quotes for electric gates and resin bonded driveway...eek.

 

 

[Bitpipe]

[Mr Punter]

Pointing gun and let it go off a bit before tooling. 

[Jeremy Harris]

Our landscaping guy did a great job on all the sandstone we have on our patio and pathways.  He used a very dry strong mortar mix, barely wet at all, so it was still crumbly, a bit like damp sand.  He literally brushed this over the joints, where it fell in, then went around compressing it and repeating the process until it was flush, finally lightly brushing all the excess off.

 

The result was no staining of the sandstone plus very well filled and pointed joints.  We've had no cracking or signs of grout failure at all.  Far quicker than going around with a grouting gun, I think, and less likely to stain the surface from any accidental splashes or spills.

[Ferdinand]

Good price ... who was the supplier?

[Vijay]

I read this stuff is supposed to be good and easy https://www.screwfix.com/p/sika-pave-fix-plus-compound-grey-11ltr/65248

[Bitpipe]

2 hours ago, Ferdinand said:

Good price ... who was the supplier?

 

Was a timber and stone merchant at local garden centre on A4, can provide the details. Landscaper is still surprised at the price as he's never seen it much cheaper than £45 a m2. 

1 hour ago, Vijay said:

I read this stuff is supposed to be good and easy https://www.screwfix.com/p/sika-pave-fix-plus-compound-grey-11ltr/65248

Not sure if it's impermable - quite expensive at £33 for 12m2 but I guess it's lower effort

[PeterW]

4 hours ago, Vijay said:

I read this stuff is supposed to be good and easy https://www.screwfix.com/p/sika-pave-fix-plus-compound-grey-11ltr/65248

 

It’s crap.....

 

Used it to lay a big sandstone patio and did it properly and compressed and pointed all the gaps.  Just over 2 years later it was breaking up and weeds growing through it. 

 

I use the premixed sand and cement mortar on a dry day and just pour it into the gaps - old 4pt milk container with the bottom trimmed off makes a great scoop. Brush it into the gaps then clean the excess off and a light going over with a hose on a fine mist sets it nicely.