The cheapest sealer that can be used is a water based sealer, and this option would be classified as a coating and not an impregnator. This means that this sealer will generally sit on the surface and not penetrate the surface. This also means that it will not have full oil resistance properties, so if you have a van or car oil leak on your driveway after this has been applied; this will not guarantee that stain against potentially seeping into the paving.
Resiblock trade is a commonly used sealer, https://www.resiblock.com/product/resiblock-trade/ and has many advantages over other water based sealers.
It can be used on a whole host of surfaces such as clay block, concrete and natural stone and has an added advantage of being very cost effective. Coverage is 2 metre squared per litre for areas that have had sand jointing or 4 metre squared on mortar surfaces, and we have often used this exact sealer on many jobs. In fact Fife window cleaning services are one of Resiblocks recommended tradespeople https://www.resiblock.com/find-a/contractor/; and have found no issue with the sealer to date.
We usually apply this with a pump sprayer and apply two coats, while you may only need one coat on more permeable solvent based sealers-two resiblock trade coats does seem to offer a good level of protection. Only a few days ago I drove past a job we had carried out in the summer with this sealer, and there was no sign of weed regrowth in the paving joints. I would personally expect this sealer to last around two to three years at least, and while this may not seem very long; if you factor in the time it would take you to power wash a driveway or pay someone to do so yearly (as the weeds come through again) then it is fairly cost effective. Our driveway cleaning Dunfermline page shows some more information about the service we can offer you https://fifewindowcleaningservices.co.uk/driveway-cleaning/
The best types of sealers to protect against things such as uv light are the ones made up with 100% acrylic polymers, with acrylic polymers being naturally totally translucent to uv light. They do not need to undergo any photochemical changes like other polymers usually do on such surfaces; and therefore offer a better degree of uv protection against fading driveways and suchlike. When we look at water based sealers the types of polymers used are all simply mixed in with the sealant; whereas with solvent based sealers polymers are already a part of the chemical mix entirely.
Because of that, solvent based sealants form a very strong impregnable bond on surfaces; the chemical balance is more intertwined and they are also classed as high volatile organic compounds-meaning they are organic chemicals with a high vapour pressure. This for our purpose does lead to more chemicals being released into the atmosphere than a water based sealer (which would be a low VOC sealer), but those solvent based sealers are also accepted to offer more long term protection.
Resiblock superior is one of the best solvent based sealers around, and is a top of the range polyurethane sealer. This particular sealer is only suitable for mono-block paving but there is a whole host of other sealers that can be used for different surfaces. The advantages speak for them self;
The application of these solvent based sealers is worth a mention too, because water-based sealers tend to take longer to congeal in a pump sprayer and so it’s important to work much more methodically with a solvent sealer and to always have a stripper nearby should the nozzle start to become jammed. Here are some key points to consider when using a solvent based sealer such as this.
Solvent-based sealers:
Blog post written by Chris Fotheringham