Patio Slab Grouting

[iamlee2002]

Hi all just some quick questions. Today ive pulled all my old grout out as alot of it came away when we had the frost winter time. Last time i grouted using the dry method. However ive read on here that wet mix will set better and be stronger.

What is the best ratio to use? 3:1 or 4:1?

Also which sand? sharp sand?

Is it best to dampen the joints first before applying the grout?

Should i use any waterproofer or plasterciser within the mix?

Will be doing this tomoz all help greatly appreciated

Lee

 

[LooPrEvil]

Use a 4:1 mix, building sand : cement.

For small areas I tend to mix the dry materials in a washing up bowl or similar, then add water until the mix will just start to bind together, it will still be pretty dry, and slightly crumbly, and when put into the gaps will not stain the paving stones. Dont dampen the joints as this will cause staining. You could lightly hose the area and let the surface dry - this will dampen the sub base which will soak into the mortar when compacted down into the joints.

Really compact the mortar into the joints, to give a better strength mortar.

Brushing a totally dry mix into the gaps is pointless, as the cement filters to the bottom, and the joints cannot be compacted as well as a 'slightly' wet mix. The mix I have described is actually known as a dry mix, but people think it means totally dry!

You dont need plasticiser. Cover the area if rain is expected within 24 hours, or frosts for the next 3 nights.

 

[russellandsons]

make sure you give all your joints a good brush out first of all you could give it a light spray over with a hose then a 4:1 mix will be fine i usually mix it semi dry like screed make sure to fill all joints fully.. and use knee pads

 

[iamlee2002]

thanks both great advice there. Better get myself some knee pads in morn

Will let you know how i get off tommorow

thanks again

Lee