Frequently Asked Questions (FAQs)
Common questions, answered
At Co-Dunkall Ltd, we understand that navigating through construction projects can raise questions. That is why we have curated this comprehensive FAQ section to address common inquiries.
Whether you are exploring our services or seeking clarification, we are here to provide clear answers. Feel free to browse through and get in touch if you need further assistance.
Floor Screeding FAQs
After being part of the industry since 2008, there is not much we do not know about Floor Screed and Underfloor Heating. Below are some of our most frequently asked Floor Screeding and Underfloor Heating questions. If you have a query or a project in mind we would love for you to get in touch.
General Questions
What is Floor Screeding?
In its simplest form floor screeding is the process of installing a level surface ready for floor finishes. Floor screeds also serve a number of other purposes including carrying underfloor heating, providing acoustic performance and offering environmental improvements.
What is Floor Screed made from?
This can vary depending on the type of screed being used. Similarly to concrete, cementitious liquid or traditional screed is made from a mixture of cement, sand and water, whereas liquid anhydrite screed is made from anhydrite binders and water. Both can be enhanced through the use of additives that alter certain characteristics of the screed, such as its strength or drying time.
What are the different types of Floor Screed?
There are a wide range of floor screeds available on the market which can be divided into two categories; liquid and traditional screed. Within these categories, there are a range of options including high strength, quick drying or thermally efficient screeds. Whether you are working to a tight deadline or have little coverage over your pipework, we can help you identify the screed your project requires!
Take a look at the different types of screed we offer here
What does a Screed do?
The purpose of a floor screed is to provide a level surface ready for floor finishes.
Where can Floor Screed be used?
Floor Screeds are designed generally for application in all non-structural, interior floors where a floor finish such as tiles or carpets are to be used. Some specialised screeds offer a wearing surface without the need for subsequent coverings.
Can Floor Screed be used to finish a floor?
In some very specialised cases yes. It is however rare and the vast majority of floor screeds require a surface covering to provide a wearing surface.
Can you use Floor Screed over an Underfloor Heating installation?
Yes. Screeds are the preferred medium for underfloor heating pipes as the material excels at absorbing and radiating warmth, becoming an integral part of the heating process. Some screeds can be used to significantly enhance the overall performance of your Underfloor Heating and the environmental impact of your floor.
Can you use Liquid Screed over Underfloor Heating?
Liquid screed is well suited for Underfloor Heating due to its high thermal conductivity and form which allows it to fully encase Underfloor Heating pipework.
Can a Screed make the floor level?
In essence, the idea of a Floor Screed is to make a floor level, so yes. If you are renovating and already have an existing floor that needs levelling off, we offer thin section screeds and latex options that may be suitable for your project.
How much does Floor Screeding cost?
Floor Screeding is incredibly cost-effective however the actual costs can vary depending on several factors such as the build size, product and depth of screed. As a company we are able to keep costs for our customers low by manufacturing our own screed, offering time saving package deals and supplying a wide range of products to choose from. For a quick and free quote, get in touch with our team!
How to work out Screed thickness
In order to work out the accurate depth of your Floor Screed you would require a laser level. That’s where we come in: we work out an average depth across your area and set levels prior to installation of any screed, so you can be sure you’re only paying for what you need.
To help our surveyors out, knowing your datum point before we arrive is always a beneficial Not sure how to work your datum point out? Contact and speak to a member of our team for today.
Types Of Floors
What are the advantages of Flow Screed over traditional forms of Floor Screeding?
Liquid Screed boasts many great advantages. It can be laid at a substantially thinner depth and is much less time consuming to install than traditional methods. One team could easily install 800-1000m2 in a day, compared to Sand and Cement Screed which could take up to 8 times longer. Liquid Screed is also self-levelling and has excellent thermal conductivity, unlike Sand and Cement Screeds.
Take a look at some of our recent liquid screed installations
What is the difference between Concreting and Floor Screed?
Concrete floors are a structural element of modern builds. They are often reinforced with steel mesh and tend to be much deeper than Floor Screeds. Concrete is often used to provide a solid subbase which can be finished using a screed. Floor Screeds aren’t used as wearing surfaces and contain no coarse aggregate. They are generally designed for interior use, whereas concrete can be used for internal and external purposes.
What is Liquid Screed?
Flowing Liquid Screed is a pump applied, self-compacting screed. It is free-flowing characteristics and versatility mean it is far less labour intensive and can generally be laid at a substantially thinner depth than conventional materials.
Liquid Screed can also be laid in large quantities at any one time. It is suitable for projects of all sizes allowing from as little as 25m2 up to and over 1000m2 to be installed in just one day.
What are the benefits of Sand and Cement Screed?
With a mix combination of sand, cement and water, this traditional type of screed is perfect for sloped finishes, wet rooms or balconies and can be strengthened further by the addition of fibres. Due to the technological development of additives such as Retanol Xtreme® and Isocrete K-Screed, traditional Sand and Cement Screeds now offer enhanced strength and faster drying times, perfect for those working to a tight deadline. Sand and Cement Screed can also sometimes be referred to as dry screed or traditional screed.
Take a look at some of our recent sand and cement screed installations
Is there a minimum thickness a Floor Screed can be?
Again, this can depend on a range of variants such as the type of screed, whether there is Underfloor Heating or whether the floor is bonded or not. For projects where depths may be an issue, we can offer thin section screeds and latexes.
The Process
Can you lay Floor Screed in any weather?
As Floor Screeds are generally designed for use indoors it is possible to lay them in any weather as long as the building is appropriately sealed. However, the governing codes of practice for screeding recommend that the temperature within the building be maintained at between 5 and 30 Degrees Celsius during the setting phase to protect the screed. The manufacturers of the screed also have specific guidance in the form of British Standards which can sometimes differ.
Our team will liaise with you if outside temperatures indicate they may affect your job.
How to prepare for a Floor Screed
Preparation is key to a successful Floor Screed. There are many steps to ensuring your floor preparation has been completed to the highest standard so for more advice on this, give our team a call. Alternatively, why not leave it to the experts and have us complete all preparation works for you. Most of our customers find this to be greatly beneficial in saving them time on site.
Fancy giving it a go yourself? Take a look at our Useful Information page for advice
How is Floor Screed laid?
This varies greatly and will depend on the size and nature of the project as well as the type of Floor Screed selected. We are happy to offer you comprehensive guidance on the best screed.
Is Floor Screed self-levelling?
To put it simply, no. Liquid Screed is self-compacting and self-smoothing but we still have to carry out specialised installation equipment and finishing techniques to get it flat and level. We usually work within the British Standard guidance for SR2 or better.
How long does Floor Screed take to dry?
This varies depending on the type of screed selected. We can offer screeds that dry in just a few hours where time is extremely critical and screeds that take much longer where time is not an issue. We can discuss with you the program for your project and help you to select the correct screed.
How to ensure Floor Screed dries correctly
Screeds dry best in warm dry and well-ventilated areas so the key is to ensure these conditions are maintained. Some screeds can be force dried using Underfloor Heating which, if done correctly can reduce drying times vary considerably. A moisture test should be completed prior to the installation of any floor coverings.
How do I know if my Screed is dry?
Prior to the installation of floor coverings, all screeds must be moisture tested to establish the water content within the said screed. All good flooring contractors will ensure a moisture test is carried out prior to the install of finishes.
Do Floor Screeds crack?
All floor screeds have the potential to crack however the chance of this can be minimised by good preparation, controlled temperatures and movement joints.
Aftercare
Once laid, do Floor Screeds require maintenance?
Floor screeds do require appropriate preparation prior to the installation of floor coverings, which may well require maintenance, however the Floor Screed itself should require little to no maintenance for its lifetime.
If I want to cover my Screed with another type of flooring, will any further preparation be required?
This can vary depending on what flooring you intend to use and the moisture content still in your screed. To lay a bonded floor covering the British Standard recommends that the floor be clean, dry, sound and free from contamination likely to cause a failure of adhesion. Proper preparation is key to a successful floor covering installation.
You must ensure a moisture test is completed prior to any floor coverings. For more information on this, get in touch with our team.
What is Latexing?
Latexing is the application of a smoothing compound to a screed that is not sufficiently smooth to receive the subsequent floor covering. The need for latexing depends on the type of floor covering used as well as the level of flatness and smoothness achieved with the screed.
What are Saw Cuts, and why are they needed?
Saw Cuts allow movement in the screed or concrete as it cures, releasing stress points that can cause cracking. This can vary from job to job, as well as from screed to screed with different screeds requiring different levels of jointing. You can discuss this in detail with our team to ensure that you can optimise the design of your project.
Underfloor Heating FAQs
General Questions
What is Underfloor Heating?
Underfloor Heating (commonly known as UFH) is a heating alternative to radiators and is installed under a screeded floor.
What are the benefits of Underfloor Heating?
There are many benefits to Underfloor Heating such as comfort, hygiene, and economic savings. Due to an even distribution of heat, Underfloor Heating allows for better efficiency and is also a great way to save you on energy bills in the long term.
What type of Underfloor Heating is best, wet or electric?
This can depend on the application. Wet Underfloor Heating systems have better thermal performance and are cheaper to run, however electric underfloor heating systems do not require a screed and may be better suited for areas with not enough coverage such as renovations.
How does a wet Underfloor Heating system work?
Warm water is distributed through a circuit of pipes that are encased in screed under a finished floor. The heat rises through the surface of the floor and into the room, working as a huge radiator. The temperature of the room can be easily adjusted and controlled by wired or wireless thermostats. The even distribution of heat from the ground upwards allows the room to warm up quicker and hold it’s the temperature for longer, unlike radiators which burn through a lot more energy to heat a room to the same extent.
How does an electric Underfloor Heating system work?
An electric Underfloor Heating system works by sending an electric current through a wire in the floor. Once the system is turned on the current heats up the wire, in turn heating up the screed and/or final floor finish above. Electric Underfloor Heating can be installed under a screed or beneath a 10mm levelling compound.
What type of buildings are suitable for an Underfloor Heating installation?
Due to its cost efficiency and easy control systems, this makes Underfloor Heating suited to domestic or commercial use, whether it’s for a kitchen, lounge, office or school.
Can Underfloor Heating be used as the primary heat source in the building?
Yes, Underfloor Heating can be used instead of or as well as radiators
Do I need insulation with Underfloor Heating?
Yes, insulation increases the efficiency of the Underfloor Heating system used.
How much insulation do I need for Underfloor Heating?
This can depend on your build’s design. Most new builds will require a minimum of 75-150mm of insulation. Some existing buildings can either use thinner insulation or an insulated quilt providing there is insulation in the existing slab.
Installation
Does Underfloor Heating have to be installed on the ground floor?
No, Underfloor Heating can be installed on any floor using a wet or electric system.
What Floor Screed works best over the top of Underfloor Heating?
We advise using Liquid Screed over Underfloor Heating due to its high thermal conductivity however traditional screed can also be used. If using Liquid Screed on smaller projects we can prepare, install Underfloor Heating and screed on the same day, saving time on your build.
Can I lay Underfloor Heating in any weather?
Yes, however we recommend that anti-freeze is used when your Underfloor Heating is installed in the colder months.
How thick does the Floor Screed need to be on top of Underfloor Heating?
This can range depending on the type of screed you install. Whether it’s a gypsum liquid screed or a high strength product can affect the depth a screed should be with Underfloor Heating.
Aftercare
Does Underfloor Heating require a lot of maintenance?
Once installed and commissioned, we recommend an annual service the same as with boilers and heat pumps.
