English Sandstone Paving Cleaned with Tile Doctor Patio & Brick Driveway Cleaner

Black Limestone Issues

When it comes to external stone Black Limestone deserves a special mention. Its a very attractive stone that can be sourced very cheaply for as little as £20m2 or less. Having said that we don't recommend this stone for external use and buyers need to be wary as its not an easy stone to maintain due to Limestone being being very sensitive to acids. Use of brick acids and harsh chemicals on this stone can quite literally bleach the black oils in the stone and damage the surface leaving it looking grey. Strong power washing and bad weather can also degrade the appearance of the stone.

Click the following link to read more about maintaining Black Limestone.

Black Limestone Patio Ruined with Brick Acid in Highclere Village

Sealing, To seal or not to seal ?

Outdoor stone doesn't require a seal, in nature it is not sealed, it looks great when it wet and a bit dull when its dry, if you power wash in the spring and again in summer this is all you have to do to it, no need for any chemicals if there is no sealer present.

If you do decide to seal, make sure the stone is free from existing sealers and is clean and as dust free as possible. Check the weather forecast before applying as new sealer will not take kindly to rain upon its surface until it has been fully cured (normally 24 hours ). Always seal on a warm day, it doesn't have to be sunny, in fact direct sunlight on a bright day can dry out the seal to quickly. You need a warm, slightly cloudy day with no hint of rain, not just on the day you seal but the following day as you will need a full 24 hours for the new sealer to fully cure, although you should be able to lightly walk on the stone or tiles with in 4 to 6 hours.

Always conduct a small test on a small area before you seal the whole, this will indicate how the sealed stone will look and make sure the sealer is compatible with the stone and recommended for external use.

Once sealed don't use any strong cleaners such as Bleach, Flash or everyday cleaners which are not pH neutral as these will degrade the new sealer prematurely. We see this problem a lot at Tile Doctor so we created a Neutral Cleaner especially for cleaning sealed tile and stone surfaces. This product can be applied with your power washer using a wide fan.

How long does a sealer last outside. Many factors will effect the longevity of a sealer applied externally. The most significant being the weather. Temperatures below minus 5 degrees can lead to the sealer disintegrating and if this happens it will need removing come the spring.

Sealing Products Recommended for External use

• Colour Grow is a colour enhancing matt finish sealer this can be used on any stone, rough, semi riven or honed. Its fully breathable and frost proof up to but not exceeding minus 5 degrees.
• Ultra Seal is a natural look matt finish sealer, once fully dry the stone will not look any different to how it looked before. With a similar specification to Colour Grow it can be used on any type of stone, rough, semi, riven, honed and polished. This product is also a good grout sealer as it doesn't darken the tone of the grout line.
• X-Tra Seal is an Impregnating sealer with strong water and stain repellency and UV protection that makes it ideal for Outdoor use. Its fully breathable and frost proof up to but not exceeding minus 5 degrees. The 1st coat will revive the colour of tile and stone and the 2nd coat, if needed, will give a low sheen satin finish sealer.

Please note: Ceramic and Porcelain Tiles generally don't require sealing but the grout will benefit from an application of sealer. Therefore we recommend Tile Doctor Ultra Seal for use along the grout lines. This is best applied with a pipette to save mess or it can be brushed on but if using this method make sure to polish off any excess from the adjacent tile or stone using a clean cloth.

For many examples of Patio and Driveway cleaning activities carried out by UK Tile Doctors please visit https://patio.tilecleaning.co.uk.

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