When it comes to choosing the right products for your project, you need to consider more than just the cost of materials. The project timeline, building usage, footfall and final finish must also be taken into account.
So, how exactly does each of these affect whether you should use pre-bagged screed or sand and cement screed? Let’s start with the basics, the difference between the two.
While both are made from similar raw materials, pre-bagged screed has all the ingredients combined before it reaches site, so when it arrives it simply needs the correct volume of water added.
Traditional screeds need to be batched onsite with a mix of sand and cement (usually 4:1) with a potential for other materials such as aggregate, plasticisers or fibres depending on the installation.
Sand and cement is a tried and tested method that has been used in the industry for decades. However, switching to a pre-bagged screed provides a range of additional benefits:
Pre-bagged screeds are liquid in nature and can be applied via a pump which can offer up to 90% time saving when compared to the labour involved with traditional sand and cement.
With this high speed of application, a team could screed over 3 tennis courts in just one day!*
| Traditional | Pre-mixed | |
|---|---|---|
| Installation | 100-150m2 per day | 600-1000m2 per day |
| Time before foot traffic (20oC & 60% RH) | 24 hours+ | 2-3 hours |
| Drying time (prior to final floor covering) | 7 days** - 12 weeks | 3 hours - 3 weeks*** |
*Applying at a rate of 4 tonnes/hour for 7 hours, this would allow 800m2 at 20mm to be covered – a tennis court is 260.9m2.
** Application of a damp proof membrane or use of a cement binder would be required to achieve this drying time.
*** Depending on floor covering.
Pre-bagged screed is manufactured in a quality-controlled environment. This same level of quality assurance can’t be replicated when the sand and cement is mixed on site, making the process open to human error as it is entirely dependent on the skills of the applicator
Pre-bagged screeds can also offer additional benefits such as self-smoothing levelling compounds and Weber’s Low Dust Technology™ formulation which significantly reduces airborne dust created during the pouring and mixing process.
Compared to traditional sand and cement screed, pre-bagged screeds require considerably less product. Traditional methods require a minimum thickness of 65mm when used on a floating floor; that’s 40mm more than weberfloor fibre rapid 4320 which only requires a minimum of 25mm or 20mm when unbonded.
Installing a traditional sand and cement floor can be back breaking work. Man-handling the material into position followed by levelling and smoothing on hands and knees.
In comparison pre-bagged liquid screed can be pumped into place requiring a lot less physical exertion and time, using just a wobble bar to finish the material.
Choosing a pre-bagged screed also means you benefit from the manufacturer's services, many who will provide technical support and assistance to ensure that the best products for the job are used and applied using best practice methods.
Pre-bagged products are often supported with material guarantees which offers both the applicator and the client peace of mind.
We hope this comparison between pre-bagged and traditional screeds has been helpful to you.
If you're looking to switch to a pre-bagged floor screed, take a look at our weberfloor range of products which are supported with a 10-year material guarantee.
Choosing a trusted brand like Weber means you benefit from our service as well as our products. We provide specialist technical support for both specifiers and contractors, and on site Weber’s applications team is available to assist with more unusual projects or help those who are new to the products get to grips with the range and the process.
For any other queries, our technical team is available to answer your questions: