Laying Floors Outdoors
Neil Sanders on installing exterior floor finishes
THIS month I will discuss working on exterior subfloors, and the challenges associated with them. From heavy footfall to extreme weather, there are many issues a contractor must be aware of when specifying products to use on outdoor flooring.
Outdoor flooring can be subjected to harsh winter frosts or, at other times, scorching summer heat, extremes that indoor flooring will never experience. Additionally, there is high footfall that outdoor areas, such as walkways, patios and balconies, are subjected to. Hence contractors must select durable products designed to meet the challenges of outdoor installations.
Weather and walkways: External floors must, at different times, endure sustained rainfall, as well as damp and cold. So products installed outdoors must be able to resist high levels of moisture and remain dimensionally stable. Also, with fluctuation between daytime heat and night-time cold, outdoor flooring solutions must also be able to tolerate extreme temperatures changes.
These conditions can cause traditional smoothing underlayments to crack or weather prematurely. Specialist outdoor products, including exterior floor levelling compounds and repair mortars, limit the amount of expansion and shrinkage caused by summer sun and winter frost, thus maintaining the integrity of the subfloor.
Certain areas may require a floorcovering such as rubber flooring on a walkway or artificial grass on a sports area. Traffic levels in such areas will be high, increasing wear and tear that can lead to erosion over time, potentially creating trip and fall hazards. To maintain a safe, even surface, it is recommended that a specialist exterior floor levelling compound be used, so that the new floorcovering can bond correctly to the surface to create a smooth, secure finish.
n Specifying specialist products: With surfaces that have already become heavily worn or damaged, with holes or depressions up to 50mm deep, we recommend the use of its exterior repair mortar, a specialist product for repairing external floors before installing an exterior levelling compound.
This product can be used for the non-structural repair of floor screeds, concrete paving slabs and other lower strength concrete elements. Also suitable for producing gradient ramps, this product has been designed for use in damp conditions, as well as promoting freeze/thaw resistance.
When an external area needs to be resurfaced, a hardwearing exterior floor levelling compound should be used. External levelling compounds can be used to create a preparatory surface, ready to receive rubber or artificial grass floorcoverings. However, to improve the slip resistance when installed as a stand-alone wearcoat, it is recommended that once the product is dry, a final ‘scratch coat’ is applied and then brushed to create a textured surface.
Finally, as previously mentioned, floorcoverings can also be installed over exterior floor levelling compounds for additional safety or aesthetics. In these circumstances, an appropriate adhesive, formulated for outdoor use, should be selected. Polyurethane adhesives are a good choice, as once cured they are resistant to water, grease and oil.
As with any flooring installation, taking time to understand the needs of the environment, as well as specifying specialist products, is the key to lasting success. By using the right products, contractors can guarantee new floors that withstand the elements and meet the needs of pedestrians.
Neil Sanders is technical director for
F Ball and Co n T: 01538 361633
This article has been reproduced from the Contract Flooring Journal. You can find them at www.contractflooringjournal.co.uk.