laying flags for patio

[bobfitz]

im just about to lay flags for a patio ive followed the the requirements of putting 200mm of hardcore and compacted that down, im going to put weed surpressant fabric down also, what i would like to know is it ok to lay the flags on top of sand (which will 2 inch compacted) with or without cement underneath or can i just butt them up together any advice is welcomed

 

[Thermo]

dont bother with the fabric it is not needed and will do nothing.

You can lay them on a bed of sharp sand compacted down and screeded off to give a level surface. You need to make sure each slab is bedded down well and does not rock otherwise the pointing will come out.

Most slabs should not be butted together as it allows for no movement in the slabs.

You would be better off wet laying them on a bed of mortar, over a layer of mot. it will give a much better result.

 

[WabbitPoo]

im just about to lay flags for a patio ive followed the the requirements of putting 200mm of hardcore and compacted that down, im going to put weed surpressant fabric down also, what i would like to know is it ok to lay the flags on top of sand (which will 2 inch compacted) with or without cement underneath or can i just butt them up together any advice is welcomed

8" of hardcore? Is it a driveway? ah, no I see from your post its not. Sounds like you've done a lot of hard work for nowt to me. IMHO you'll get a better 9and rather easier to attain) result by using a wet mortar bed as described above, especially if the slabs are at all riven (and hence have different thicknesses). For a casual DIYer, I think bedding on sand is doomed to failure. Just my 2p worth

 

[Thermo]

have to agree with you wabbitpoo (again)

 

[skybluescooby]

Take it from me, a dry mix screeded level is NOT the way forward.
I spent a full week doing what you have done, 2" of mot i may hasten to add, looked superb until settled then i found rocking, cracked joints and then the frost got in and lifted some. I have just spent the last 2 days lifting it and relaying on a wet mix, Nearly done and looking better than the last one

 

[Thermo]

got any pics yet scooby?

not much more work than the first way you did it either is it?

 

[skybluescooby]

No pics yet Thermo, Just got out of shower and sat with a couple of becks looking for best advice on the pointing mix, Some say 3/4 to 1 with sharp and building ? Others say 3/1 just sharp ?
Got the last run to relay tomorrow, approx 20 slabs then point in the afternoon, back permitting. ANY ADVICE ?
Funny thing is i tinkered on wet lay first time round but due to time restrictions has to go for a dry mix.
Best advice i can give to OP is to listen to others and listen well

 

[Thermo]

right listen and listen well. Youve done the hard work, but the pointing is what makes or breaks the appearance of the job.

If the weather is like it is today ie very hot then leave it until a cooler morning. the slabs will heat up like storage heatrs during the day and they will cook off the cement before it has time to adhere. If you havnt got the time then do a very small area at a time. Once its done spray the area with a fine mist of water, just to ****** the drying of the cement. Do it a few times till th temperature cools off.

The mix.
Use 1:3 cement and building sand....thats building sand!! dont use sharp sand.
Measure out each mix carfully using a small bucket or tub to measure each one, dont do it by the trowelful etc. only mix up as much as you can use in half an hour. get it damp, and have a small watering acn with you just to drop a touch in as about halfway though use as it will dry out quickly in this weather. Do not use any of the suff you leave on the surface. As soon as cement dries it will grey off. Its hydrated and dried and is now a useless powder so you dont want it in your joints. Once youve done a small area joint it up with your jointing tool.

final tip, get a cushion, a radio and a drink. Enjoy the pointing as you go its your reward after all the back breaking work. Also watch your eyes, with a light coloured slab you wont belive how much glare you get off of the slabs when your pointing them up. Its a bit like snow glare!

hope that makes sense

 

[skybluescooby]

Ok,
So, Patio cools down around 1pm as the sun is blocked by the new garden room.
What length of time following laying is deemed as too soon,
So would a light spray prior to pointing suffice, also i read somewhere or saw it on Ground Force that to tackle the heat pour a little amount of water into the void then put the mix on top before pressing with jointing tool You also say , get it damp, did i read somewhere that it's best to bet it pliable so it can be moulded by hand and allowed to fall without sticking
My new signature---Why do i complicate things

 

[Thermo]

yes, yes and yes