January 2020

Top Tips: Liquid Applications
TOP TIPS: LIQUID ROOFING AND
WATERPROOFING APPLICATION
Kemper System’s Ross Smith, who was crowned Trainer of the Year at the Liquid Roofing
and Waterproofing (LRWA) Awards 2019, shares his top tips on how to effectively and
safely apply liquid products.
The growth of the liquid roofing and waterproofing industry has provided contractors with more
product choice than ever before. But regardless of the type of liquid solution being applied, there
are some important steps to follow to ensure the system performs to the required standard and
the roof remains waterproof for many years to come.
“Don’t assume that all
liquid waterproofing
products are the same”
1Research your product With such a large
number of liquid roofing products now
available, take the time to research which
one is most suitable for your project.
We’ve seen some new manufacturers offer
liquids through distributors at low prices
which claim guarantees of around
25 years. Contractors need to
tread carefully and establish
whether a product is
suitable for the purposes
intended. If not, you risk
applying a product which may
not perform effectively.
As a first step, consider requirements such as
compliance with building regulations – for
example fire resistance – or specific performance
characteristics, including the compatibility of the
surfaces to be waterproofed, ability to withstand
substrate movement, and resistance to damage
from anticipated load levels or trafficking.
Independent product accreditation is used to
effectively communicate conformity and
suitability, so it is advisable to research the
manufacturer’s current product certification. An
example is BBA certification, but there are others.
If in any doubt about the suitability of a product,
the Liquid Roofing and Waterproofing Association
(LRWA) may be able to assist.
2Prepare thoroughly The
importance of substrate
preparation can’t be
underestimated. Without the
correct preparation, there is a
chance that the liquid installation will
fail prematurely.
Before applying roof coatings, ensure
the surfaces to be coated are firmly
fixed and free from any
contaminants that could prevent
the primer or membrane from
adhering properly. To remove oil and
grease, use manufacturer-approved
detergents and for organic growth such as
moss, use an approved fungicidal wash.
Most primers and coatings require a dry surface to
maximise the adhesion. Refer to the manufacturer’s
product guide for specific information.
Surface profile is also important. Applying a liquid
to a rough surface such as concrete will increase
consumption and therefore your costs. In this
situation, it may be more cost effective to
mechanically prepare the peaks in the substrate
or fill the troughs with an approved material to
flatten the profile. Generally, a coating will
perform better under stress if it is applied to a
uniform thickness.
Conversely, smooth metal surfaces may need to
be abraded. This will normally improve adhesion.
Left: Ross Smith, Kemper System.
3Follow the manufacturer’s
instructions – to the letter
Don’t assume that all liquid
waterproofing products are the
same. Each one is different and so the
manufacturer will have its own set of
instructions and recommendations for effective
application, including suitable substrates, surface
preparation, mixing and application.
Take advantage of manufacturers’ training
courses to ensure you’re fully up to speed on the
product to be used and how to apply it. When on
the roof, don’t be tempted to cut corners – review
and follow all the steps and advice listed by the
manufacturer for all stages of installation.
4Keep safe You should refer to product
material safety datasheets and be fully
aware of how to store, transport, use and
dispose of the products in a safe manner. The
information contained in such documents is
essential for the writing of risk assessments and
method statements when planning their use.
Responsible liquid waterproofing manufacturers
will be able to provide advice, support and training
in the safe use of their products.
Contact Kemper System
01925 445532
www.kempersystem.co.uk
@KemperSystemUK
24 TC JANUARY 2020