Learn how to lift and relay block paving. There can be nothing worse on a driveway or patio than an area of sunken or uneven paving blocks. It looks untidy, leaves puddles every time it rains and can create trip points. Here we look at how to lift and relay block paving with our easy-to-follow guide.
The good thing about block paving is that with a little knowledge you can easily lift and relay block paving. You should be able to leave no trace of your paving ever being uneven. Or that it had ever been lifted and relaid.
How to Lift and relay block paving
It is always best to choose a dry day to lift and relay block paving.
First you need to decide which areas of paving are going be taken up and re-laid. To help you decide which areas are uneven and need to taken up and relaid, you need to use something solid and straight. You could use a straight piece of timber or a spirit level. Place it on the paving and look at the area underneath the straight edge to determine which area is to be laid again. You could also pay particular attention to your paving when it rains for a period of time. Mark out the puddled areas when it’s wet. Or maybe take a photo of the area with standing water when the paving is wet. Use the photo to give you a visual aide when your ready to relay your block paving.
By looking under the straight-edged timber you will be able to see the dips and hollows in the paving. Next, you need to mark out these areas around the perimeter of the paving to be re-laid. You could use a chalk mark. Or with some other form of method you see appropriate. Tip – You could use bricks placed on top of the paving. String, a hose pipe or even small sticks placed along the joints of the paving. These are all helpful ways of marking out the area. Either way, the paving we are going to take up and re-lay needs to be marked out. This is to stop you taking up the whole block pavers.
1. Lift & remove the area of uneven block paving
Once you have decided which area of paving you are going to re-lay and you have marked the area (so you don’t end up taking up the whole block paving) you need to break into the paving.
This is usually the hardest part of the job. The idea is to remove the jointing sand between the blocks so that the sunken blocks become loose. Once you have loosened a few blocks you will find that the rest of the bricks are quite easy to remove.
You could use a specialist paving lifting tool kit designed to lift out block paving. These can be expensive to buy though. Other ways could use a club hammer and chisel to smash and break the difficult paving blocks (usually needed). Although this process will leave you a block or two short when you come to relaying the paving. As the broken paving blocks will not be reusable. Other methods include gently cutting along the joints of the paving with a stone saw to loosen the blocks. Or even using a strong leaf blower to try to remove the sand between the joints of the paving.
I have even know people jet wash out the sand with a power washer (although this method is not recommended). It all depends on how tight the paving blocks are! If they are very tightly locked together then its going to be difficult to remove the paving. Likewise, if the pavers are loose then its very easy to remove the paving bricks.
You need to remove the pavers individually. Then stack the paving close to the job but not where it will interfere with the relaying process.
2. Clean the paving you have removed
Important – As you stack the paving bricks it’s important that you give them a good clean with a small stiff brush to remove any ‘stuck on’ sand. This could be screened grit sand on the base or joint sand on the sides of the paviors. This will help when you replace the paving bricks by keeping the replaced paving bricks tight against the other bricks and level with the new level sand. It will ensure that your paving fits back into the pattern. That way you won’t go out-of-line & get gaps in your paving.
3. Level up the uneven area with grit sand
NOTE* Before you begin to level up the area that has sunk with grit sand it may be worth investigating why the paving had sunk in the first place? If you are confident that it is not because of a broken drain or inadequate depth and strength of the stone sub-base, you can begin to repair the paved area.
Always use grit sand and not building sand when you lift and relay block paving. You can purchase grit sand with free home delivery here. The grit sand works because it supports your paving better and allows for a better drainage should you get a penetration of water into your paving block joints. Building sand will just become soggy and hold the water rather than letting it drain through.
Grit sand is available in small 25 kg bags or large 1 tonne bags, although if you need the 1 tonne bag you have serious problems with sinking and I would call in a paving expert to give your block paving an inspection. Grit sand wherever possible should be kept out of heavy rain. This stops one area of sand being water saturated and makes laying the sand easier and lighter.
Begin by using the straight edge again to judge the amount of grit sand needed to fetch the level up to the appropriate height that is needed to level the paving with the surrounding block paving, once you have leveled your paving.
If you lift and relay block paving on a large area you can place the straight edge on top of the blocks that are level surrounding the sunken area, then measure down from the bottom of the straight edge. Then, minus the depth of your paving brick (ie. 50mm). Then you add 3-5 mm to allow for compaction (the raised sand will level out when compacting the paving later).
Example Lift and relay block paving calculator
Depth from bottom of straight edge to sunken sand area = 67 mm
Minus depth of 50mm block paving bricks. 67mm – 50mm blocks = 17mm
Then add 3mm 17mm + 3mm = 20mm (this is what you’re paving will settle once compacted down at the end of the leveling up process).
Therefore the depth of grit sand needed to lift and relay block paving bricks would be 20mm. This will then be the level at which you need to spread the new sand over the sunken area. This ensures you fill in the dip of the paving. Level and then blend the sand into the existing, surrounding grit sand to match the level of the sand with a trowel.
Other methods of leveling your sand
If you are not confident with the above method of leveling the grit sand, and it does take a bit of practice, you could use this next method.
When you think the sand is level gently place a brick on the level bed of sand. Then place the straight-edged timber on top of the block paver. If the timber is 2-3 mm above the level of the finished paving at the perimeter then that level of sand should be good. Make sure that you carefully place the paving block on different areas on the sand to check the levels at all the areas of paving that are being re-laid.
Use a small pointed trowel to spread the sand. Or use a small piece of level wood to act as a screed. A pointed end trowel is good for getting in between the square corners of the block pavers that have not been taken up. You don’t want any uneven sand close to where the paving is already laid as this will create a rise in the paving. Level the sand to existing sand.
4. Re-lay the block pavers
Once you are confident that all the sand is level you are ready to begin re-laying the blocks.
Make sure that there is no sand stuck to the sides of the paving blocks that you are placing back down. And that there is no sand stuck to the sides of the block paving that you are joining up to.
If there is, it is more than likely that this sand will distort the relaying pattern and design of the block paving. This then allows gaps to start appearing when you relay the block paving.
It will also make it difficult to put back the last few remaining block paviors because the gap is too small.
When you lift and relay block paving you may find a small rubber mallet or the wooden end of a club hammer will aid in tapping down the paving as you replace the paving. Lay the old paving tight to the already laid block paving. Follow the pattern of the existing paving. Start at the outside and work along the line of the paving block pattern.
When you get to the last few remaining pavers to be replaced you may need to tap them into place. Usually these will be fairly tight to get back into position.
4. Compact the relaid paving
It is important that any relaid block paving is compacted. But before any compaction of the block paving takes place you first need to sweep clean the paved area. This stops any debris such as small stones being vibrated down between the joints of the paving. If this happens it can distort the laying pattern and overall design of the driveway or patio.
Compaction should be done with a whacker plate or straight-edged timber & hammer. This should be done to the whole paving area 2 or 3 times. Particular attention should be made when compacting the edges of relaid paving. The paving edges need to match up to the existing paving that has not been relaid. It needs to be level to stop any trip points. Care should also be taken around sensitive areas such as walls , drains or inspection covers.
To compact the relaid paving you can use a large flat piece of timber that covers the area that has been relaid. Place the timber on the relaid block paving and firmly strike the timber several times with the hammer. Make sure you hit the wood and not the blocks. Lift the timber to check that the paving is level. Repeat until you are confident the paving has become firm and stable.
If you have relaid a small area of block paving then using a straight piece of timber should be sufficient to compact the blocks. But if you have laid a significant area of pavers or you have access to a compactor plate then our recommendation is to use this to compact your paving. If you need a compactor plate you could hire one from a good tool hire shop for around £20-£30 for a days hire.
5. Apply kiln dried sand
Once you have compacted the relaid paving it is time to apply kiln dried sand to fill the joints between the pavers. Apply the dry sand liberally to the surface allowing the sand to fill up the joints. Then sweep the surface of your paving to remove access kiln dried sand and save to one side.
Once the surface has been swept you need to re-compact the area. We repeat the process of compaction as above using the timber or compactor plate to lock the pavers together with the sand. You will notice after the compaction that the dry sand sinks into the joints of the paving. After compacting the paving a second time sweep kiln dried sand back into the joints where the sand is low.
That’s it! Your done! Stand back and admire your new level block paving.
Send us photos of your uneven or sunken paving. Or the process of how you re-laid you’re uneven paving and if we use the photos on our website we will send you a complimentary Amazon gift voucher to the value of £20.00.