The Brew Cabin

My mum had her driveway block paved last year. The driveway slopes down from street to house at about 45 degrees and as a result, the jointing sand came out when it rained and formed massive sandy pools at the bottom! This began to happen straight away and the lovely contractor never turned up to rectify despite being chased many times...

A month or two after it was laid I refilled the joints with a jointing sand/grey cement mix - being a DIY virgin it's all I could think of. This solved the problems but left a greyish cement stain all over the reddy-brown blocks. My brother recently steam cleaned it to get rid of moss, cement stainage and oil stains and now the joints are exposed and need redoing! Lucky me...

It's a big drive way (fit 4 large cars on the slope alone) - how can I fill the gaps so that:

A) the joint filling doesn't get washed away; and

B) without using cement and staining it as previously?

All tips and comments will be greatly appreciated!

Thanks in advance.

MSC

Does anyone know if there's any risk of the cars sliding off a drive like this in a severe winter ? I've got a steep drive and am always very quick with the rock salt in the winter, but have never known whether a parked car, with its tyres firmly on the drive, was at risk.

Not sure about the car sliding off the drive but in reply to the first question the best way to solve the sand being dislodged from the paving joints is to brush in some kilndried sand and use a sealant or joint stabiliser over the whole area(ask your local builders merchant). If you are going to seal the area then it may be a good idea to clean the area before resanding and sealing as you may end up sealing in dirt or marks on the block which you will not be able to remove later.
Alan.

Yes: use a joint stabilising compound or a sealant to maintain the sand in the joints of this steeply sloping pavement. The JSC just 'fixes' the sand, whereas the sealant (assuming you choose a quality product) both fixes the jointing sand and protects the surface of the blocks.

Don't ever use cement to bind jointing sand for flexible pavements - it is a recipe for disaster and does far more harm than good.

Ooops! Forgot to answer the sliding car question!

Block pavers have to meet certain standards for slip resistance before they can be sold as suitable for pavement use, and, this standard is set at a level to ensures that, even at a relatively steep gradient, let's say 1:1 (45º), the car should stay in place, p[rovided that the tyres are in good condition and the handbrake works.

It's far more likely that the handbrake would let you down before the car 'slipped' on the paving.

Thanks to all of you for your replies.

Any makes of product you guys recommend?

Also, will this sealant stuff be waterproof AND durable? We have an old mongrel who has a favourite "pee-spot" and this area, very near a tap and drain (which will therefore also have a lot of water splashing around on a daily basis) needs washing down everyday.

Oh, and just so I know for future reference, why is it not a good idea to use cement/sand mix in the joints of block paving?

(Edited by msc at 10:10 am on June 15, 2004)

For a sealant you could use Resiblock, Techcon or Hexham - all are good products. See the Sealant Links page for contact details.

The Resiblock is the creme de la creme, and you pay for it, but it really can't be over-paised. Techcon and Hexham are good, durable acrylic products that will need re-doing every 2-4 years.

And the reason why you don't use sand and cement to joint block paving is that the pavement is designed to be a flexible structure, and the joints are intended to move slightly. Adding cement turns them into rigid joints, which reduces the degree of interlock and actually results in a weaker pavement.

Apart from that, the cement stains the blocks and makes them look crap.