Screed FAQs

For a fine screed top layer, the screed will be made from sharp sand and cement. We use 6mm polypropylene fibres to help reduce surface cracking and a Retarding additive to give you longer to lay your screed.

Screed is designed to be used to level out concrete flooring or sub bases. When screed is used as a final layer it will provide smooth and even finish allowing carpet, tiling, or wooden floors to be laid evenly on top. Screed is also used on concrete flooring that have underfloor heating pipes, locking the heat in where it needs to be.

Concrete and Screed are both made of the same materials – Cement, Stone / Sand – Water. Screed however has a much smoother finish and is easier to level as it’s made using a much finer aggregate, sharp sand. Concrete on the other hand consists of more coarse aggregate than fine sharp sand giving it a much stronger and more durable finish.

Using Screed as a final layer on your concrete floor instalation offers you a more sturdy and level base for top layers such as tiling, carpeting, wood floors or resin. A well laid screed finish can also provide you with an attractive looking concrete floor if laid bare, giving the area a more industrial feel.

You may also find that you need to level out a concrete sub base or concrete foundations with a screed finish giving you this option.

The difference between having ready mixed screed or having your screed mixed by a Volumetric concrete mixer are very minor with the main advantage being that using a Volumetric concrete mixer ensures that your concrete is always fresh and that you never have excess screed, giving you greater flexibility on the job. Especially so if you find the need for a different strength screed on the fly.

It is important for any concrete flooring or sub base to be even and safe, with a gradient slope varying no more than 5mm per 3m. If your screed is laid in the correct fashion, you will have a level concrete floor to work with.

Thin section screed is a cement based that uses only a single component. This form of screed drys / cures quickly and is manufactured for the purpose of smoothing and leveling concrete floors. This process is often used on an area prior to installing a floor covering.

Thin section floor screed is used to repair concrete cracks and level the floor base so you can proceed onto the next phase of your concrete floor plans. The uses of Thin Section Screed include the following:

•  Give commercial flooring a smoother and more attractive finish
•  Filling in holes or cracks that have appeared in the concrete floor base
•  Leveling out any depressions or indents that have appeared in your concrete flooring
•  Providing a level base for the next stage of floor covering
•  Prepares the concrete floor base for the use of resins or concrete floor painting

The minimum thickness / depth of your concrete floor screed will depend on the project at hand with some of the more heavy duty projects need a much thicker depth of screed to ensure it’s strength. We always recommend consulting your builder prior to ordering. As a general rule, the follow screed depth measurements apply:

• Bonded Screed: A minimum of roughly 25mm thickness is advised
  
• Unbonded Screed: A minimum of roughly 50mm thickness is advised
  
• Floating Screed: A minimum of roughly 65mm is advised
  
• Underfloor Heating Screed: A minimum of roughly 65mm is advised.

When it comes to applications that will bear a heavy load or see a lot of commercial such as parking, or with underfloor heating, we advise to use a screed depth of 65mm. Each project will vary though and we encourage you to speak to your builder beforehand.

Yes, you can use concrete screed over underfloor heating. The concrete screed will act like an insulator and eliminates the need to use extra insulating materials.

Yes you can. The main reason to use concrete screed is to pour over a pre existing concrete floor / slab / sub base to level it out and leave a smooth finish.

You are able to pour floor screed in both wet and cold weather providing that the outdoor temperature is at a minimum of 3°c. We do however advise you to take additional precautions to ensure that the temperature remains at that minimum and that the area is watertight to achieve the best result.

You will often find that screed is mainly used for indoor or covered installations so these precautions are often a part of the screed delivery itself and as we use Volumetric mixers, our screed doesn’t risk spoiling. Please be aware that on extra hot days your screed will dry / cure quicker than normal. Retardants are available to help this process.

Screed is a durable concrete and can be poured in almost any climate. As long as the correct measures are taken in extreme temperatures and the project area is water tight.

Yes, screed makes a great finish if left bare. Many customers opt to cover their screed with some form of floor covering such as carpet, tiles or wooden flooring. A bare screed floor can be used in a more commercial project or a project that is looking for a minimalist finish. Leveling screeds are generally non-wearing surfaces, and should always be protected.

Screed is predominantly used as an inside application but it can be used outdoors. Depending on the project you will often find that regular concrete is a better option due to it being much stronger and durable but screed has it’s place with applications such as outdoorpaving or decking, giving you a more level surface to work with.

Screed can be pumped directly to the job site using a specialised concrete screed pump. It can also be delivered with ease using a Volumetric mixer from our fleet at 365 Concrete. The extendable chutes on the Volumetric truck allows us an additional 5m of reach, so more often than not, we can pour your screed direct.

Yes you can. A mixture of sharp sand and cement is ideal for the majority of concrete screed projects, including those projects that feature the additional of underfloor heating.

Depending on the thickness of the screed, the time will vary. As a general rule, your screed should be left to dry / cure for a minimum of 24 to 48 hours before you walk on it. If you opt to use admixtures in your screed, the drying time can be reduced to 12 hours.

Industry guidelines state a 75mm traditional screed would require up to 110 days to dry at 20˚C and 50% RH at the rate of 1mm per day for the first 40mm and 0.5 mm thereafter.

We advise that screed should be left to cure for a minimum of 24 to 48 hours before you walk on it. If you have opted to use additives and admixtures with your screed, this intial curing time can be reduced. Please speak with your builder or our team at 365 Concrete regarding admixtures to have a clear idea of when it can be walked on.

It’s important to note that screed, and all products made of cement, have the ability to shrink and reduce in size as they dry / cure / set. You will need to allow up to 28 days for your screed to dry / cure / set completely before you begin to add tiling or any other floor covering.

Additives and admixtures can be used to reduce this time, please contact your builder or the team at 365 Concrete for more information on this.

There are a few different ways that you can prepare your concrete base for screed, such as:

• Floor Crack and Joint repairing
• Scarifying
• Diamond Grinding the top surface
• Shot Blasting

If your screed has been laid correctly, you will not need any additional maintenance. Your screed should maintain to be fault free without any flaws.

You can use a ‘Self Leveling’ floor screed which has a much more free flowing consistancy. This screed will level itself, hence the name.

For normal screed, once it has been poured into the required location you will be able to level the screed using a flat based wooden float. Using 4 level anchor points of the concrete screed area, pull the wooden float in a downwards motion to flatten the screed, with the intial 4 anchor points as a guide line.

Using our free concrete calculator is the easiest way to get your measurements right. Simply add your measurements into the required field. We’ll be happy to work out your screed measurements with you, just give us a call.

Sunlight is not a major concern when it comes to screed but it is important that your screed maintains a certain amount of moisture when it is curing / drying to ensure it sets at full strength.

If you are laying your screed outdoors under direct sunlight or extreme heat in general, you should be prepared to cover the screed area with a tarpaulin or plastic sheet. This will help to prevent it drying out too soon.

Yes, it is important and beneficial to screed over your underfloor heating. Not only does the screed protect your under-flooring heating pipes but also helps prolong the heating effects due to the screed retaining the warmth.

An important stage if installing underfloor heating is to screed over the top of it. The screed helps protect your under-flooring, protecting the heating pipes and acting as an insulator.

For concrete flooring it is important to finish off the concrete with a layer of screed. Without this top screed level you will have extreme difficulties leveling the floor well enough to apply your final finish of carpets, tiling, wooden floorboards etc.

When it comes to laying paving slabs, it is not essential that you use screed. It does however offer you additional benefits if you choose to use it.

With a screed base you will have a more level area to lay your paving on and with the addition of a retardant to your screed, you will be able to work with the surface area longer before it sets / cures / dries.

Screed is a great concrete to work with as there is little to no care needed after the concrete screed has set / cured / dried. Providing you have laid your screed properly there, you should be good to go.

If you’re screeding over a pre-laid concrete floor it’s important to make sure that the flooring is clear from debris or rubble that may affect your screed finish. This is a common area in commercial or industrial sites. Always make sure you give the area a sweep first.

Traditional dry concrete screed is not self-leveling and will require you to manually level it using a flat wooden based trowel. Liquid Screed is however self-leveling.

Screed is a multipurpose concrete top layer and can be used in all premises including domestic / residential, commercial, industrial and even agricultural properties. Admixtures can be used with your screed if it’s laid to be used for heavy loads or traffic.

Yes, screed is an adaptable concrete and can be custom tailored to provide acoustic proofing.

We say yes. When it comes to underfloor heating, screed as a top layer helps to retain the heat and insulate the underfloor heating and also offers an additional level of protection of the heating pipes.

There are four standard types of screed which are listed below. However, if you choose to use an admixture with your screed, different effects will be applied.

• Bonded Screed: This form of screed is normally applied when you are in need of a thinner layer of screed. It is a fully bonded screed to be applied on a concrete sub-base / flooring. This screed is mixed with a bonding agent or primer.
• Unbonded Screed: This is mainly used on older concrete slabs and floors and is laid onto either some form of polythene sheeting or damp proof membrane, separating it from the pre-existing concrete floor.
• Floating Screed: This is used as a top layer on thermal insulation installations. It’s designed to be laid on top of some form of damp proof membrane which separates the screed from the existing concrete floor or sub-base.
• Underfloor Heating Screed: This form of screed is similar to Floating Screed and is designed to be used as an insulator for underfloor heating pipes. This saves you needing additional insulating materials.

Yes. If screed is laid correctly then you will be left with a completely level surface which is ready to the final layer installed.