For optimum performance we recommend that paving is cleaned twice a year.
Fill the joints
When permeable paving is first laid we often find that there is some settlement of the jointing material and so it is important to top up these joints with 6.3 –2 mm grit after a few weeks. Indeed, it is also important that, at any time during the life of the pavement, the joints are kept full of grit. Please check carefully that you are using the correct grade of joining grit.
WARNING – do not replace the jointing grit with sand as the sand will block the joints and stop the permeable system from working.
Vacuum sweepers
Please do not use vacuum sweepers as they can suck
the grip out of the joints.
The surface layer (Hydropave blocks)
Initial Cleaning
When an area has just been paved, please allow it to settle for a few weeks. Then, you may wish to lightly hose down the paving to remove any excess dirt. The area should then be treated with a weed killer suppressant, two or three times a year as required.
General Dirt
Regular sweeping to prevent the build up of detritus is recommended. Light coloured blocks, emphasise tyre marks and oil spills on the pavement. It must be accepted that these products will need more maintenance if the overall appearance is to be maintained.
A light power hose at medium pressure is generally all that is required to clean general dirt and grime. Any jointing grit, which has been removed must be replaced. Do not use high pressure power washers as aggressive power-washing can damage the product surface and dislodge the jointing grit.
The joints between the Hydropave blocks
It is important to ensure that the grit filled joints do not become blocked, as the water will not be able to flow into the sub-base. Experience has shown that joints have good permeability for many years. However, it is good practice to brush the joints with a stiff brush, to break the crust of detritus, which inevitably forms at the top of a joint. This simple exercise improves the permeability significantly.
Care should be taken that the permeable joints do not become contaminated at the construction phase and special care needs to be taken with soft landscaping to ensure that soil does not enter the joints.
How to clean clogged joints
If the joints on a paved surface have been badly contaminated and clogged it may be necessary to clean them thoroughly. This can be done as follows:
• Remove existing jointing grit and detritus by high pressure water jet.
• Reset the pavers, which will have become displaced
Replace any damaged pavers at this time since they will have been loosened.
• Apply 6.3-2mm single size grit to the joints, using a stiff brush to sweep the material in ensuring joints are filled.
• WARNING – do not replace the jointing grit with sand as this will stop the permeable system from working.
The sub-base below the Hydropave blocks
We would strongly advise not to disrupt the sub-base below the Hydropave blocks. This sub-base is specially designed for each particular site. If you have no alternative but to disrupt the sub-base please speak to the contractor prior to disruption so you can receive clear guidance on how to reinstall the material in the correct formation.
In the event of any material being lifted and reinstated, please use the following Material Specification:
* In particular, the material should be categorised as LA20 according to
Table 9, SZ18 according to Table 10 and MDE15 according to Table 11 within this standard. The grit should be insoluble in dilute hydrochloric acid and should be naturally occurring material.
** You must ensure the grit and coarse graded aggregate are compatible. For example, if you use a finer grit it may perculate into the sub-base and may destabilise the pavement. Please refer to the following source of information – BS7533-13:2009 Pavements constructed with clay, natural stone or concrete pavers. Guide for the structural design of permeable pavements.
Click here to download the Hydropave Maintenance Document