Block Paving Driveway Draining

Chickereeeee

I am after some opinions/advice here please.

I had had the front garden and driveway refurbished with new paths, lawns etc, and block paving to the driveway. The person/company that did it came from a personal recommendation, and I am very pleased with most of the work. However, I have a concern with the draining of surface water on the drive.

At the front of the house the driveway has a noticeable slope to the road, and the usual strip-drain is in place across the threshold, with drainage to a soak-away. this area is fine. The block paving drive then runs between two houses (ours and next door) to a garage at the rear.In this area, there is very little slope (if any), and water from a hose pipe lays in pools, a few mm deep,, in certain areas. The pools cannot get TOO deep, as there are 3 surface-level drains along this area, but there is no flow towards them. Now, eventually, the water drains away - I think between the blocks - and I have not noticed significant pooling after normal rainfall, (except when a drain overflowed). But I am planning on sealing the blocks so, and I assume this would reduce any drainage between them.

The installer said he would do what I wanted to make me happy, but he would prefer to do it before sealing. It is not obvious (to me) how to arrange the fall to improve the situation. I am not sure if it is acceptable now, or would be after sealing.

Any thoughts?

Thanks

FreeBear

Block paving is supposed to be "permeable" - i.e. Water will filter through the gaps between each paver and drain away in the sub-base. Some short term pooling is to be expected in flat areas, but it the water should disappear fairly quickly. Sealing the pavers shouldn't be an issue as it is the sand between the blocks that allows the water to drain away.

The paving should slope towards any drainage channels, so you want to get the installer to correct it if possible.

Chickereeeee

FreeBear said:

Block paving is supposed to be "permeable" - i.e. Water will filter through the gaps between each paver and drain away in the sub-base. Some short term pooling is to be expected in flat areas, but it the water should disappear fairly quickly. Sealing the pavers shouldn't be an issue as it is the sand between the blocks that allows the water to drain away.

The paving should slope towards any drainage channels, so you want to get the installer to correct it if possible.

OK, thanks for the input. So. sealing the block paving also 'stabilises' the sand in the joints. You are saying this will not appreciably its ability drain? That's good, if so. It would be a significant effort to appreciably change the fall, and I do not to make him do it if not needed.

FreeBear

Sealing the pavers won't appreciably affect the drainage. But you don't want to flood the sand with the sealer. Might be an idea to rake the joints with a knife after sealing and brush some fresh kiln dried sand in.

Chickereeeee

FreeBear said:

Sealing the pavers won't appreciably affect the drainage. But you don't want to flood the sand with the sealer. Might be an idea to rake the joints with a knife after sealing and brush some fresh kiln dried sand in.

Hmm, that would seem to undermine a major reason for doing the sealing.

Plus, Resiblock have just said that it WOULD prevent water draining between the blocks.

C

GDB2222

It seems a contradiction to have block paving and then seal it. That’s going to cause water to pool. 

Chickereeeee

GDB2222 said:

It seems a contradiction to have block paving and then seal it. That’s going to cause water to pool. 

Not if (as in many/most cases) the block paving has a slope. Indeed, the government insist that such drives are treated as non-permeable to rain water, and must have a drain leading to a soakaway to prevent overloading the local sewer/drainage systems. The thought behind sealing is  to reduce staining on the blocks, but also mostly to stabilise the sand against migration and weed growth.

grumbler

That's how block paving has to be shaped if done correctly. No puddles and you can see here two 'valleys' running to rain water drains. It's almost 30y.o. BTW.

FreeBear

grumbler said: That's how block paving has to be shaped if done correctly. No puddles and you can see here two 'valleys' running to rain water drains.

And how not to do it...