Screed: What is it?

February 27, 2022/0 Comments/in Fire Protection, Home Page news feed, News /by Georgia Robertson

Screed is similar to concrete but is less well-known outside of the construction industry. Nonetheless, it can be an important part of any build.

Screed can be described as a thin material that is placed on top of a concrete subfloor, usually consisting of cement and sharp sand. Coarse aggregates can also be added to create a thicker layer. The layer of screed can be covered with a decorative finish, but in some cases can be left bare, such as in warehouses, where scuffs and marks can be expected. It can also be used as a flooring choice.

There are 3 main types of screeds, bonded, unbonded and floating. Bonded can be applied directly to the concrete base and is bonded, as the name suggests, to the base using a bonding agent. This is a common method for environments where heavy loads are expected and where there is no room for use of unbonded screed.

Unbonded screed can be applied on top of a damp proof membrane. This screed is at least 50 millimetres thick and the fact it is not bonded to the main structure means that settlement and shrinkage risks are reduced.

Floating is used an insulation layer of material. This is most common where underfloor heating is apparent. Typically, the thickness of this screed is around 65 millimetres for lightly loaded floors and 75 millimetres for heavy loaded floors. If using a calcium sulphate screed, 35mm depth will be sufficient for domestic use, and 40mm necessary for commercial applications.

A main reason as to why floor screed is used in homes, despite its extra expense, is to level uneven flooring. This is especially important with modern precast concrete beam and block floors, which have a distinct camber that can cause problems when it comes to laying floor finishes.

If you have any questions on screeding, please get in touch.

Exterior Insulation Finishing Systems (EIFS)

January 25, 2022/0 Comments/in Fire Protection, Home Page news feed, News /by Georgia Robertson

An Exterior Insulation Finishing System (EIFS) can also be known as Exterior Wall Insulation Systems (EWI) or External Thermal Insulation Composite Systems (ETICS). It is a type of cladding system that can provide exterior walls with an insulated finish surface and waterproofing in an integrated composite material system.

These systems can be defined as an ideal energy efficient thermal wrapping or façade insulation, which is applied to the exterior surfaces of a building. It is then finished with a long-life and protective wall coating that can be installed on any type of construction.

Versions of EIFS

Barrier EIFS – A barrier EIFS, which can also be known as traditional or conventional EIFS, can be applied to a solid wall (brick, blockwork, pre-cast panels etc).

EIFS with drainage – This is a type of barrier EIFS, to which a water drainage capability can be added. This is usually done for wood structures.

How do EIFS save energy?

It can be argued that EIFS are unique as they are the best exterior cladding system that offers thermal control, as well as adding improved energy efficiency to the home. EIFS with drainage can help to reduce a household’s carbon footprint and keep energy costs down.

These exterior cladding systems can help to improve the airtightness of the building envelope, which is one of the most critical elements of energy-efficient home construction.

However, most insulation boards used in EIFS is either made from expanded polystyrene or polymer-modified systems. Both products are synthetic and can come with some environmental drawbacks. Polystyrene degrades slowly, and when it is properly disposed of, the foam can leach chemicals which can harm water sources. Also, many recycling centres will not accept expanded polystyrene as it is a relatively low-value product. Therefore, it can be incredibly difficult to get rid of.

Are EIFS healthy?

When properly installed, EIFS do not have any health consequences. However, improper installation techniques and older variations of EIFS that did not include specific drainage systems have been proven to lead to serious mould growth, which can have impacts on the health of the occupants of the building. The mould growth can also damage the structure of the building, which can lead to expensive repairs.

According to the National Association of Home Builders (NAHB), homes with barrier EIFS are “prone to moisture intrusion problems even when properly constructed according to industry standards. Unlike other cladding types, the design of barrier EIFS does not allow the draining of water that gets behind the system, either through building components (openings in the building envelope for doors, windows, etc.) or when sealants break down or crack. Depending upon the climate and the wall assembly’s overall make-up, the wall may not readily dry out. Sustained elevated levels of moisture without adequate drying will cause rot or decay to sheathing and framing.”

If you have any questions on Exterior Insulation Finishing Systems, please get in touch.

Types of commercial fire alarm systems

December 14, 2021/0 Comments/in Fire Protection, Home Page news feed, News /by Georgia Robertson

Fire alarm systems are incredibly important in any type of occupied building as its purpose is to alert the occupants of a hazard and the right system could potentially save lives. It’s also important to understand the differences between different fire alarm systems.

Automatic versus manual fire alarm systems

There are 2 different categories of fire alarms that you can have in a commercial space: manual or automatic. When automatic alarms detect heat or smoke, they send an audio-visual alert throughout the building to alert the occupants of danger. Manual fire alarms will have pull stations stationed around the building. When a fire is seen or smelled by one of the employees, they simply pull the leveller and alert the occupants. Manual alarms come in a variety of designs and colours.

Commercial fire alarm system types

There are different types of fire alarm as well as categories.

Conventional

Conventional fire alarms include several different “zones” that are hardwired to the central control panel. These systems allow you to be able to put separate fire alarms in each section of your building and helps to monitor if an alarm is broken.

Addressable fire alarms

These fire alarms can also be known as intelligent systems. This is because they monitor the fire alarms within your building. Addressable alarms allow you to choose between automatic and manual alarms. The alarms that are installed in this system have their own address, which allows visibility to see which alarm is working and which are failing. These fire alarms are more expensive due to the monitoring features.

Hybrid fire alarms

These alarms combine the hardwired zone features of conventional fire alarms with the addressable loops of the addressable fire alarms into a single panel. This combined technology fits some of the settings better than either the addressable or the conventional alarm.

If you have any questions regarding fire alarm systems, please get in touch.

Dry lining: what is it?

November 10, 2021/0 Comments/in Fire Protection, Home Page news feed, News /by Georgia Robertson

Dry lining is a form of cladding that prepares internal walls and, occasionally, ceilings, for painting or covering. A smooth surface is created by attaching plasterboard.

This method is quicker than plastering, which is a similar process. Dry lining also uses specialist materials which can save money and time. Plastering also uses more water than dry lining does, which is why the term is ‘dry lining’.

Why is it used?

Dry lining produces a similar result to plastering but is much quicker. Simply put, it produces a surface or wall that is ready to paint or cover. This method can hide wires and pipes, and can even provide sound boarding, and also create an insulation space.

Brickwork and uneven surfaces can be covered with dry lining, making it suitable for a range of applications. It can even create curved walls, which can be incredibly beneficial when dealing with small surfaces or unique spaces.

Dry lining can also be added to stud walls, which are often used in newer models of buildings.

Where can it be used?

Dry lining is usually used on internal ceilings and walls (such as uneven surfaces and brick walls) and on internal stud walls. There are two standard sizes of thickness of plasterboard that can be used, 9.5mm and 12.5mm, depending on the surface that the plasterboard is being fixed to.

In bathrooms and kitchens, dry lining can be used, but moisture-resistant plasterboard or specialist insulation must be used in order to combat the condensation that may be produced in these locations.

What materials can be used?

Plasterboard is the main material that will be used in the process, and this can come in many shapes and sizes. This is then affixed to produce the smooth surface. However, this isn’t the only material required. Nails, screws, and adhesives will also be used in the process.

The adhesive will be used to attach plasterboard directly to the internal wall using dabs of quick drying adhesive. This can be called the dob and dab method. Plasterboard can also be attached to timber or metal walls using nails. This technique is known as tacking. However, screws can hold plasterboard in place better than nails, so the screwing technique can also be used.

In order to cover nails or screws sticking out of the plasterboard, water can be mixed with a powder, which is then combined to make a paste and spread over the nails or screws. Once this substance dries, a smooth finish can be created by sanding it down. Tape can be used to cover any joints between the sheets of plasterboard.

What is plastering and why is it different?

A wet substance is used when plastering, that utilises different materials dependent on the required finish in order to cover a wall. It can then be covered over or painted when it dries. However, this method takes far longer, as the plaster takes far longer to dry. For some older properties though, plastering is preferred in order to maintain the style of the building. Architectural mouldings can also be created using the plastering technique, which cannot be done using dry lining.

In conclusion, there are many benefits to dry lining, and there are also some disadvantages, such as dry-lined walls being more subjected to damage.

If you have any questions regarding dry lining, please get in touch, we’d be happy to help.

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