Pressure washing is an important part of preparing a patio or driveway for sealing, but it is not always enough on its own. A good clean needs to remove more than loose dirt and surface grime if you want your sealer to bond properly and give you a long-lasting finish.
Here at Swiss Seal, we always recommend taking the time to prepare the surface properly before reaching for the sealer. It might take a little longer, but it can make a big difference to the finished job.
Does pressure washing remove everything before sealing?
No, pressure washing removes loose dirt and grime, but it may not deal with ingrained stains, algae, moss, oil or other contamination.
A pressure washer is excellent for shifting years of accumulated muck, particularly from block paving and concrete surfaces. However, some contaminants can remain behind even after the surface looks clean.
This is where using a suitable patio cleaner or driveway cleaner can help. At Swiss Seal, we have a range of cleaners designed for outdoor surfaces, helping you deal with the dirt and organic growth that a pressure washer alone may leave behind.
Should you use a patio cleaner before pressure washing?
Yes, using a suitable cleaner as part of your preparation can help loosen stubborn contamination before pressure washing.
Rather than simply blasting the surface and hoping for the best, apply the appropriate cleaner according to its instructions and allow it to work as directed. You can then pressure wash the surface thoroughly.
For particularly dirty patios, this two-stage approach can give you a much cleaner surface ready for sealing.
Do you need to remove weeds before sealing block paving?
Yes, weeds should be removed from block paving before sealing, including growth around the joints.
Pressure washing can remove some weeds and debris, but it is important to make sure unwanted growth is dealt with properly before applying a sealer. Any remaining organic material can affect the appearance of the finished surface and potentially cause problems later.
It is also worth checking the joints and replacing or repairing any jointing material where necessary before sealing.
Does the driveway or patio need to be completely dry?
Yes, the surface should be properly dry before applying sealer.
This is one of the easiest preparation steps to overlook, particularly here in the UK where the weather has a habit of doing exactly what it likes. After pressure washing, give the surface plenty of time to dry before sealing.
Applying sealer to a damp surface can affect how well it bonds and may lead to an uneven finish.
What should you do after pressure washing?
After pressure washing, inspect the whole surface, deal with remaining stains or organic growth, make any necessary repairs and allow everything to dry thoroughly.
Here at Swiss Seal, we supply cleaners, repair products and sealers for a range of outdoor surfaces, including block paving, natural stone, concrete and imprinted concrete.
So, while pressure washing is an excellent starting point, don't treat it as the whole preparation job. A properly cleaned, repaired and dry surface gives your sealer the best possible chance of doing its job properly - and that's what we're aiming for.