Hello all
Our drive is about 100sq m, laid in block paving, I estimate about 15 years ago. It needs cleaning, and also has several areas of minor ponding and rutting, where it has settled. The rutting is not severe, suggesting the sub base is reasonable. Will I be able to uplift the existing blocks, relevel the subbase and reuse the blocks? Local contractor has suggested it is too expensive to clean off the edges of the blocks before relaying them, and I should buy new blocks. This seems a good way to generate sales of blocks!
Assuming I can do as I propose, can I work in smaller areas, or do I need to do the entire drive as one area?
Thank you - a great website, I have learnt a lot.
Relaying existing block paving
-
Paverman Dan
- Posts: 70
- Joined: Tue Jun 29, 2004 5:27 am
I'm disinclined to think that cleaning sand or screenings off the edges of each block with a square trowel is a huge deal, though I'd probably add a slight labor upcharge for it. Of bigger concern is what is underneath those pavers. What setting bed material was used above the sub-grade? That would have to be removed before addressing the subbase, and once that is done, the setting bed would need to be re-set.
I would unzip the entire pavement, make the assumed to be minor sub-base improvements, then re-set the setting bed, and re-instate the pavers. But more information is needed.
I would unzip the entire pavement, make the assumed to be minor sub-base improvements, then re-set the setting bed, and re-instate the pavers. But more information is needed.
-
Tony McC
- Site Admin
- Posts: 8346
- Joined: Mon Jul 05, 2004 7:27 pm
- Location: Warrington, People's Republic of South Lancashire
- Contact:
The contractor is trying to beef up his profit. There's abso-bloody-lutely nothing wrong with cleaning off existing blocks and re-using. In fact, Interpave devote a whole document to the reinstatement of block pavements.
I reckon it takes around 10 seconds max to clean off a block; that's 500 seconds per square metre, or 8mins and 20 seconds. Even if you're paying a labourer 100 quid per day for an 8 hour shift, then it works out at a rate of 1.73 quid per square metre.
You have 100m², and assuming the blocks are 60mm deep (quite likely if they're 15 years old), that means they would cube-up to a volume of 6m³, or roughly 14 tonnes. To throw away that quantity of blocks is going to need at least two skips at, say 125 quid apiece.
Replacement blocks are roughly 10 quid per square metre, so that's a grand for your 100m², plus the 250 quid in skips to throw away perfectly good blocks.
How does this eejit work out that it's not cost efficient to clean-up the old blocks? Hasn't he got a calculator?
In the past, the way that I've found works best when 'rejuvenating' a driveway such as this is as follows: (must make this into a webpage when I get the time!)
1 - Clean the existing paving, using a power washer if poss. This ensures any really naff blocks can be identified immediately, the blocks are 'like new' when being re-laid, and it avoids the problem of you not being able to power-wash a 'new' drive for at least 3 months after installation.
2 - lift blocks and stack out of the way. Lift as many or as few as you feel you can handle. If you lift all 100m², your drive may well be out of commission for a week, but if you were to do, say, 10-20m² at a time, you could have them lifted and relaid on the same day.
3 - remove ALL laying course sand and bin it. DO NOT RE-USE. There are very sound technical reasons why it's not a good idea to re-use the old sand, but I'll not bore you with them at this juncture.
4 - check sub-base, re-grade and re-compact as necessary, adding extra sub-base material to any areas that are low and ensuring you end up with a tolerance of ± 10mm.
5 - place and screed to level NEW grit sand laying course
6 - take blocks from store, ensure sides are free from any old jointing sand, and re-lay
7 - cut-in new pieces at edges. It's unlikely old cuts will fit, but you can try, if you wish. Cut new blocks, rather than cutting the older blocks as this will help ensure you have the shiny new pieces only at the edges and not as 'sore thumbs' within the body of the pavement.
8 - jointing sand and consolidation as soon as poss.
If you're working on small areas at a time, it's unlikely that you will be able to fit in the new exactly to "close" the paving at the end of each session. Leave out a course or two and fill that with the laying courses sand. This will help keep the blocks in place until the next session and allow you to consolidate without the newly-laid blocks flying loose. At the start of the next session, lift two or three courses of the previous session's work to ensure you get a smooth transition, as it's quite likely that those last couple of courses will have moved if held in place by a bit of sand.
That's the gist of it - it really isn't difficult and you should only need a single pack (at most) or replacement blocks, not the whole 100m²!!
I reckon it takes around 10 seconds max to clean off a block; that's 500 seconds per square metre, or 8mins and 20 seconds. Even if you're paying a labourer 100 quid per day for an 8 hour shift, then it works out at a rate of 1.73 quid per square metre.
You have 100m², and assuming the blocks are 60mm deep (quite likely if they're 15 years old), that means they would cube-up to a volume of 6m³, or roughly 14 tonnes. To throw away that quantity of blocks is going to need at least two skips at, say 125 quid apiece.
Replacement blocks are roughly 10 quid per square metre, so that's a grand for your 100m², plus the 250 quid in skips to throw away perfectly good blocks.
How does this eejit work out that it's not cost efficient to clean-up the old blocks? Hasn't he got a calculator?
In the past, the way that I've found works best when 'rejuvenating' a driveway such as this is as follows: (must make this into a webpage when I get the time!)
1 - Clean the existing paving, using a power washer if poss. This ensures any really naff blocks can be identified immediately, the blocks are 'like new' when being re-laid, and it avoids the problem of you not being able to power-wash a 'new' drive for at least 3 months after installation.
2 - lift blocks and stack out of the way. Lift as many or as few as you feel you can handle. If you lift all 100m², your drive may well be out of commission for a week, but if you were to do, say, 10-20m² at a time, you could have them lifted and relaid on the same day.
3 - remove ALL laying course sand and bin it. DO NOT RE-USE. There are very sound technical reasons why it's not a good idea to re-use the old sand, but I'll not bore you with them at this juncture.
4 - check sub-base, re-grade and re-compact as necessary, adding extra sub-base material to any areas that are low and ensuring you end up with a tolerance of ± 10mm.
5 - place and screed to level NEW grit sand laying course
6 - take blocks from store, ensure sides are free from any old jointing sand, and re-lay
7 - cut-in new pieces at edges. It's unlikely old cuts will fit, but you can try, if you wish. Cut new blocks, rather than cutting the older blocks as this will help ensure you have the shiny new pieces only at the edges and not as 'sore thumbs' within the body of the pavement.
8 - jointing sand and consolidation as soon as poss.
If you're working on small areas at a time, it's unlikely that you will be able to fit in the new exactly to "close" the paving at the end of each session. Leave out a course or two and fill that with the laying courses sand. This will help keep the blocks in place until the next session and allow you to consolidate without the newly-laid blocks flying loose. At the start of the next session, lift two or three courses of the previous session's work to ensure you get a smooth transition, as it's quite likely that those last couple of courses will have moved if held in place by a bit of sand.
That's the gist of it - it really isn't difficult and you should only need a single pack (at most) or replacement blocks, not the whole 100m²!!
Site Agent - Pavingexpert