Natural Stone Surfaces – External Application
Cleaning, Sealing and Maintaining Natural Stone – Part Three
Natural stone has been used as an external surface covering for paths, driveways, patios, court yards, terraces, porch areas,verandas, loggia and sun decks for centuries. As with all natural materials, it does need a certain level of care.
This is the third in a 16 part series of posts that will offer a comprehensive guide to cleaning, sealing and maintaining all types of stone, porcelain, quarry, terracotta and glazed ceramic tiles and surfaces. This post explains the LTP three-step approach to cleaning, protecting and maintaining natural stone surfaces used in external applications such as paths, driveways, patios, court yards, terraces, porch areas,verandas, loggia and sun decks. Natural riven or rough cut stones are often used outside because they are naturally slip resistant. Normally thicker than internally fixed stone they are more robust and harder wearing. The following guide will explain the process and help keep your surfaces maintained and in good condition for many years.
Natural Stone Surfaces – External Application
The following instructions are for sawn and honed, riven or rough cut finish: sandstone, slate, granite, quartzite and rough cut and riven limestone.
Step one: Initial cleaning
Before sealing, clean natural stone thoroughly to make sure that the surface is sealed effectively. This is true of newly installed surfaces, as well as existing, due to the contamination that can occur during fitting. On existing surfaces such as patios, driveways, paths and terraces remove old layers of sealer, dirt residues and light deposits of organic matter and algae from the surface and pores of the stone. For newly installed surfaces cleaning should remove all grout and cement residue and any general dirt or grime that has built up while fitting. Bucket, mop, sponge, scrubbing-brush or scrubber dryer machine if available.
Newly installed surfaces
Before grouting and once surfaces are clean and dry: Apply one coat of LTP Colour Intensifier & Stainblock before grouting. This treatment will help with the removal of residual cement and grout from the surface of the stone paths, driveways, patios, court yards, terraces, porch areas, verandas, loggia and sun decks. LTP recommends using LTP Grout Stain Remover to clean and remove residual grout and mortar from the textured riven surface of natural stone driveways, patios, court yards, paths, stone terraces,verandas, porch areas and sun decks once they have been laid.
Please note: Do not use LTP Grout Stain Remover on honed and smooth limestone.
This product is only suitable for use on riven limestone.
Cleaning newly installed reclaimed flagstones, rough cut, honed and tumbled stone surfaces
- Dilute LTP Grout Stain Remover 1:2 with water. On rough cut limestone dilute 1:6
- Apply solution to the surface with a stiff brush and agitate immediately.
- Leave for 5 minutes and agitate again. Rinse well with water.
- Rinse well with plenty of clean water.
- Allow the surface to dry.
Refurbishing used and heavily soiled stone surfaces
- Before sealing the clean stone thoroughly. Old layers of sealer, dirt residues and light deposits of organic matter and algae must be removed from the surface and pores of the stone.
- Dilute LTP Grimex 1:3 with water, apply to the surface with a sponge or water brush and leave to sit on the surface of the tiles for as long as it takes for the dirt to release. 5-30 minutes depending upon the level of dirt.
- Agitate the surface with a stiff deck brush every 5-10 minutes (scrubber machines can be used).
- Continue to scrub while adding clean water. Remove residues from the surface with water or scrubber machine.
- Rinse thoroughly with clean fresh water to remove all remaining residues. Use a power washer if necessary.
- Allow the surface a minimum of 3 dry and damp free days before applying the protective seal.
- For the removal of other types of dirt refer to the table below.
- Do not allow the sealer to dry on the surface. Carefully buff with a soft cloth or machine to remove any excess. Complete this within 1 hour of application.
For the removal of other types of dirt refer to the list below. If you are unsure please call our helpline for advice.
- Cement residues and mineral salt formations – use LTP Grout Stain Remover.
- Tar, wax, paint, bitumen residues – LTP Solvex and then LTP Power Stripper.
- Deeply ingrained oil stains – LTP Spot Stain Remover and LTP Fullers Earth.
- Algae deposits and general dirt and grime – LTP Grimex.
- Organic matter – LTP Grout Stain Remover.
Step two: Protect your natural stone surface from stains
To protects sawn and honed, riven or rough cut finish: sandstone, slate, granite, quartzite and rough cut and riven limestone surfaces and help prevent staining LTP recommends the application of LTP Colour Intensifier & Stainblock.
The equipment you will need for this task: bucket, applicator, brush, cloth.
Application of LTP Colour Intensifier Stainblock: Enhanced natural finish protects against water, oil, grease, dirt, grime, organic matter and aids maintenance
- Clean surfaces and ensure they are dry.
- Apply the product to the surface evenly using a sponge, brush or soft cloth.
- Redistribute to remove excess product and avoid pooling on the surface.
- Allow to dry. Do not walk on the surface for at least 3 hours.
- Protect from damp and wet conditions for at least 3 days.
Step three: Maintaining your reclaimed flagstones, rough cut, honed and tumbled stone surfaces
Using the correct maintenance product will increase the life of your stone seal, provide more protection against staining and make sure your path, driveway, patio, court-yard, terrace, porch area, veranda, loggia or sun deck looks great. Common household cleaning products often contain harsh substances that can breakdown sealing products applied to stone. For this reason LTP recommends using LTP Grimex on external surfaces sealed with LTP Colour Intensifier & Stainblock. LTP Grimex will remove surface dirt when required (normally every 3-6 months).
Regular maintenance on sawn and honed, riven or rough cut finish: sandstone, slate, granite, quartzite and rough cut and riven limestone
- Dilute LTP Grimex 1:3 with water.
- Apply the solution to the surface and agitate.
- Leave for 10 minutes before agitating again and then rinse with water.
- Leave to dry for 24 hours and then if necessary re-apply a light coat of sealer.
- Protect from damp and wet conditions for a minimum of 3 days.
Should you use a professional floor restoration company?
The application techniques described above are achievable by a competent DIY enthusiast using the products as described. However, natural stone products are often expensive and by nature each stone has its own characteristics. We often find that many of our customers prefer to use the experience and skills of a professional stone restoration and cleaning company to make sure that their project is completed to the highest standard. LTP is pleased to associate with the following companies that specialise in natural stone restoration and cleaning:
PLEASE NOTE: Always follow the detailed instructions on the product labels. Protect stone surfaces from contact with acidic substances. Do not use abrasive materials on honed or polished stones. Avoid using normal detergents or strong bleach cleaners on sealed surfaces as they will gradually remove the protective seal.
At LTP we believe in helping to offer solutions and this is why we offer a no obligation
LTP TECHNICAL HELPLINE, so please give us a call on +44 (0) 1823 666213 and we will be happy to help you.
Visit www.ltp-online.co.uk to buy from the LTP Range of products or find out more about us.
- Natural Stone Surfaces – Traditional and Ageing Method (ltpuktechnical.wordpress.com)