Procedures

Dust Management

Prior to submitting an estimate for work MJB assess the dust management requirements.  This takes account of the potential for dust generation and the difficulty of providing appropriate protection.

Depending on the specific requirements assessed for the job one or more of the following measures may be implemented to minimise and control dust:

  • Laying of tough polycarbonate sheeting to protect floor coverings in working areas and material storage areas.
  • Laying of purpose made self adhesive floor covering protection in areas which will experience foot traffic. This is much superior to conventional dust sheeting because it is impermeable and safer because it does not present a trip hazard and although smooth is a low slip surface which does not move.
  • Installation of polythene sheeting to protect furniture and other items from dust. Where practicable and feasible without damage to the protected item this may be sealed with adhesive or adhesive tape.
  • Installation of tough polycarbonate sheeting, plywood boards etc, to protect furniture and other items from dust and mechanical damage.
  • Provision of foot mats to minimise transfer of dust and debris by foot traffic.
  • Installation of a temporary dust extraction system comprising a powerful fan with temporary ducting to an outside location. This system serves two purposes. Firstly it establishes a small under-pressure within the room so that air is drawn into the room around door seals etc thus eliminating or minimising dust egress from the room. Secondly airborne dust is discharged from the room. It is not always feasible to install this system but in many cases an existing ceiling fan can be removed to allow the discharge ducting to be utilised and reinstated when the job is finished.
  • Installation of temporary sealing around doors and/or other openings to prevent dust egress.

Silicone Sealing (Shower Enclosures, Bath, Basin Etc)

It is normal practice to use a bead of silicone sealant to seal various joints such as the junction between a shower tray and the shower enclosure, the junction between a bath or basin and the wall etc.  Silicone sealant is a very good material in this application but has limitations:

  • Over time waste material such as soap can accumulate in microscopic crevices present in the silicone. Bacteria can grow on this material and cause discolouration.
  • Silicone will eventually start to break down becoming unsightly – and lose adhesion to the substrate compromising seal integrity.

We minimise these tendencies by:

  • Selecting a top quality silicone with antibacterial additives.
  • Employing a special applicator to minimise micro-crevices which can harbour bacteria and lead to discolouration.
  • Careful degreasing of the surfaces using solvents selected for compatibility prior to sealant application.

Silicone Re-Sealing

Once cured it is very difficult if not impossible to completely remove a bead of silicone sealant without damaging the substrate – even though the remaining layer of silicone may not be visible to the naked eye.  Cured silicone may be removed mechanically with cutting tools and/or abrasives but it is very difficult if not impossible to completely remove the silicone without damaging the substrate.  Chemicals are available which attack the silicone and assist in its removal.  These chemicals can damage the substrate but we have found modern chemicals increasingly less likely to do so – although we do test for compatibility before use.

Silicone sealant does not bond well to previously cured silicone sealant.

For these reasons a bead of silicone sealant installed after removing a previously installed silicone bead may prove to be unreliable after a relatively short period.  In these circumstances it may be possible to achieve a reliable seal by some other method or the seal may have to be replaced again earlier than might be hoped.

Shower Board versus Tiles

Shower boards have certain advantages and as might be expected disadvantages compared to tiles in bathroom applications.

Some but by no means all shower boards are effectively completely waterproof.  Tiles on the other hand whilst often themselves effectively waterproof strongly rely on other components to achieve a water resistant installation.   Tile grout may be described as ‘water proof’ but in many cases this means that the grout is not damaged by water rather than impervious to water.  Epoxy grouts are usually impervious to water but they are costly to buy and to install.  It is therefore appropriate to ensure that the substrate is waterproof either by installing suitably waterproof boarding instead of conventional plasterboard or by applying a ‘tanking’ coating designed for this type of application.  A suitable tile adhesive is also required to enable trouble free service over a long period to be achieved.

A number of different types of shower board are available.  Some of the best known utilise a wood based backing material such as MDF or plywood.  Such backing materials tend not to be very tolerant of water.  We do not recommend such products.  Instead we recommend selecting a shower board which comprises only waterproof materials.  A number of such products are available and we are happy to recommend and provide further information.

Tiling can be cleaned but the grout between the tiles may eventually become stained despite regular cleaning.  Grouting can be replaced but this is time consuming if the result is to be both attractive and water tight.  Shower boards are easier to clean although it is essential that only suitable cleaning materials are used to avoid surface damage.

Shower Tray

We prefer an acrylic capped stone resin (or equivalent) shower tray of reasonable depth.  Where feasible a perimeter upstand is recommended.  This can be adhered to the shower tray or preferably integral.

Lower cost plastic shower trays tend to be more flexible.  Flexing stresses the sealing around the tray and can lead to failure and leakage.

A shallow trays can overflow without the user noticing until exiting the shower cubicle by which time extensive flooding can have occurred.  The user is much more likely to notice a rise in water level before overflow occurs if a depth of about two inches or more is required before overflow can occur.

An upstand or lip around part or all of shower tray reduces the likelihood of problems in the future as a result of seal failure. The shower enclosure (tiles, shower boards, doors etc) fits just inside the upstand so local failure of the seal does not result in water egress from the shower tray.  Note however that if the sealant is removed or fails completely then water can jet under the bottom of the shower enclosure and over the upstand.

If it is required to eliminate the step into the shower enclosure then a wet room type approach can be adopted.  In some applications this may have functional and/or aesthetic advantages which justify the additional cost and other disadvantages.