Re-laying block paving to mix with flags

[Andyb01]

Hi All

Looking to lift and relay a fairly large back garden patio and paths (around 75m2 in all) which we originally laid ourselves around 12 years ago. It's held up pretty well and is laid on a base of compacted hardcore (about 150mm from memory) and then a 50mm compacted sharp sand screed. Reason for re-laying is following a new conservatory build and want to re-use existing pavers (but won't have enough as we want to change the shape and make it bigger in some areas) and combine with slabs to square off the curves (too many cuts).

Not sure if this combo approach is a good idea and how easy it is to combine the two types - i.e. which do you lay first?

Ground is heavy clay (we're talking the kind of subsoil you could throw a decent pot from) hence the need for a sub base last time. Really keen to avoid a sharp sand only bed due to hordes of ants invading the existing paving laying course - esp near the house wall.

Any advice on the best kind of base and laying course to use - give the above and tips on levlling the brick pavers and slabs would be welcome.

Thanks in advance

Andy

[msh paving]

You need to study the main site, everything you need to know is there......MSH

[Andyb01]

You need to study the main site, everything you need to know is there......MSH

OK thanks for that - I did spend about an hour or so actually reading up on the main site and didn't find anything on laying mixed paving like this - obviously I didn't look hard enough.

[Tony McC]

Assuming the flags and blocks are the same thickness, they can be laid onto a single screeded laying course. You;d work exactly as detailed on the main site: get your edge courses in first to define and contain the area, then infill with full elements before doing any necessary cutting-in.

I can't provide detailed info on mixed paving as there are just so many possible combinations. Occasionally, as outline above, two paving types can be combined in one method, but more often, you have to lay each individually, following the advice given on the main site. So, if you were laying granite setts and block pavers, you'd need to lay the setts first then infill with the blocks. Each job has to be undertaken on its own merits.

[lutonlagerlout]

when mixing blocks and flags i find it best to lay as if all of it was a slabbed patio and lay them all on 40 mm of 10:1 grit sand :cement bedding layer on 100mm subbase.
got to make sure your falls are set up correctly as any dips or peaks will be accentuated by this type of paving
LLL

[Andyb01]

Cheers guys - very helpful - presumably I have to tamp the block pavers down by hand as the plan will have them in double or triple rows interspersed with an area of slabs and I can't use a whacker plate on the entire thing once the slabs are in?

Noted about the falls - I recall we had some fun with them last time as it needed to fall in two planes in one place (away from conservatory and house walls) but got them right in the end.

[GB_Groundworks]

see this thread from a few years ago


flag/block post

[Andyb01]

Cheers for that link very helpful. Also considering extending by just adding more paviors (existing is in 60mm concrete block brindle) and I need an additional 20 sq m after marking out so was looking at some charcoal ones as a contrast. Here in lies the problem. I can get 60 mm concrete block paviors from a few sources locally but the spacers are in the wrong place. What I mean by that is that they are different to my existing blocks which means that - when laid in a herring bone or any other pattern and mixed with the old blocks - the two spacers touch which will create a 3mm gap instead of a 1.5mm one. My existing paviors were from a local building supplier (own branded) about 12 years ago (since taken over) and it seems that nobody makes them with the spacers like mine any more.

From what I have read on the site, laying them like this (new grey paviors as an edge with the old brindle as the infill) will compromise the strength of the patio and it will look odd as certain parts of the paving will have wider joints (and yes I have checked to make sure my existing paviors have not been laid upside down before you ask!) :;):

Looks like I either have to work with in the area I can cover with my existing blocks, use flags as the contrast or junk the lot and start again! Any advice on this appreciated.

Thanks

Andy

[GB_Groundworks]

depending on the length of your join you could remove the spacers on the first row of blocks, lay them then you'd be back to normal spacings, and use the new blocks.

[ambient]

you could chip the spacers off the first row with a lump hammer or chipping hammer only needs to be the two spacers touching the old row make sure you tap them from side not top you might chip top ???

[Andyb01]

Yep - tried chipping a few off but tends to be unpredictable results. Some come off clean and others chip the top so don't fancy that as a solution as will waste loads.

Going to have to re-think - sure didn't predict this one!

[ambient]

if you have stihl saw you can grind them off ???

[Andyb01]

Well after much research I finally tracked down some blocks with the nibs in the right place! Decided just to extend the existing patio using additional blocks and have been busy reading up on the site learning all the things I did wrong last time! The main one being the edging where I just haunched in on the sub base against a block laid on top of compacted sand (clearly a big no no).

I entirely get the point about 'edges first' but paving away from the house to up to 4m I'm concerned that the edge fit may be less than perfect by the time I get there with the blocks (based on an honest assessment of my own capability). So I am torn between the floating edge and the bed replacement approach. I can see how bed replacement works but, for floating edge, I assume the idea is that the edge blocks are placed on the concrete bed after it's gone off (sorry to be thick but it doesn't actually say) and then align to the final block after laying it on the screed and then haunch behind it with a fresh mix?

It looks to me like bed replacement is the potentially stronger of the two, as you can tamp into wet concrete to a finished level and haunch at the same time (yes?) and then whack the rest of the blocks the next day after the edge has gone off.

Have I got his right?

The other question I have at this stage is regarding concrete mixes for bedding and haunching the edge blocks. Not sure if I need ST4 for this or ST1 (or even ST1 to bed and ST4 for haunching). If someone could advise, that would be really helpful. The existing paving has a curved edge but I'm binning that in favour of straight lines (fewer cuts and hopefully a better finish).

Cheers in advance guys - brilliant site btw

Andy

[lutonlagerlout]

i hear ye
if you lay it to finish ,then take up the blocks at the edges and dig down 150 mm (carefully of course) fill with lean mix and tap the blocks in to place this will work well
think this is what you mean
I do this sometimes as it is not always feasible to have kerbs if for instance a drive runs into a narrow path beside a house (need to get wheelie bin up tight gap)
its detailed elsewhere on the main site
cheers LLL

[Andyb01]

Cheers - think that's what I'll do. What about the first edge course that goes up against the house wall (I'm actually paving off two walls in one place, the house and a conservatory). Does that edge course just sit on sub base and compacted/ screeded sand or is it recommended that this is also bedded on concrete? I couldn't find an exact reference to this on the edges courses part of the site. I know that under our existing paving we have problems with ants underneath it and it did strike me that bedding the soldier course up against the house on concrete might help deter the little b..........

I also intend to use a good quality sealant on this paving after it has been laid (something else I have learned from experience) which should also help keep out 'mining insects' as I believe they are sometimes called.