The Brew Cabin

i laid some flags a few days ago (using a 1:10 cement / coarse sand mix for the bedding layer)

i now want to adjust the positions of these flags a bit, but the bedding layer underneath has started to set slightly, with a crust forming on the top

i can break up and crumble the crust fairly easily, and re-lay on that... or would it be more advisable to rake out some the debris of the crust, and replace with fresh cement/sand mix...?

also, for some flags, i can crowbar them to slide them along into the desired slightly new position (only an inch or two along/re-angled), and they seem solid with no wobbles, but should i really be lifting them up and re-bedding them for a good long-term result...?

thanks,
james

If you need to re-lay, you need to use a new bedding material. Break up the old stuff and mix in some fresh cement.

The flags that you've barred into a new alignment should be ok - if there's no rocking or wobbling now, there'll be none when you get around to joiting them. :)

Can I read into your answer that if I have some gone-off bedding material I can re-use it by adding another 1 part cement?

I have been struggling against the elements to get my flags laid and managed about 1/4 of the job over the weekend before the heavens opened and the job was rained off. Therefore I have nearly 2 barrows of bedding that I was worried was no use...

You can re-use old bedding material, as long as you break it up to a sand-like consistency again before adding the fresh cement.