Which Finishing Methods Are Suitable For Siniat Boards?

Guidance on taping and jointing, skimming, tiling and decorating Siniat plasterboards.

Table of Contents

Overview

Siniat boards can be finished using a range of methods depending on the board type and service environment.

The finishing methods would be Taping and Jointing or Skimming (Siniat does not manufacture skim plaster products) in preparation for final finish such as Tiling or Decoration.  

Not all Siniat boards are suitable for every finishing method. Guidance on board suitability is provided throughout this article and can be found in Annexes A1 to A4 of the Siniat Drywall Manual.

Compatibility of third party finishing products
In accordance with Gypsum Products Association (GPA) compatibility guidance, finishing products from major UK gypsum plaster manufacturers may generally be used on compatible Siniat boards, subject to the manufacturer's recommendations. Specialist products should always be checked with the relevant manufacturer before use.

 
 

Taping and Jointing

Annex A1: Taping and jointing is a finishing method for most Siniat drywall systems and is used to complete the wall surface, reinforce joints, and provide a smooth surface ready for desired finish.

A typical plasterboard joint consists of three stages:

  1. Bed – Joint compound is applied and Siniat Joint Tape is embedded into the taper zone.
  2. Fill – Additional compound is applied to fill the taper and cover the tape.
  3. Finish – A final finishing coat is applied to achieve a smooth decorative surface.

The bedding and filling stages are the minimum requirement to achieve the intended system performance.

The final finish coat is primarily aesthetic and may be omitted above ceiling level where the joint will remain unseen. This practice is often referred to as fire taping or smoke taping.

Siniat Joint Tape
Siniat recommends their joint tape application for full-height plasterboard joints

 
Siniat Patching Tape
Siniat Patching Tape may be used for remedial works where required.
 

Please note, Siniat Patching Tape has a lower tensile strength than Siniat Joint Tape and therefore carries an increased risk of visible cracking where movement occurs - Siniat therefore would recommend Joint Tape for full length joints.

 
 

Skimming

Annex A2: Skimming 

Most Siniat plasterboards are suitable for skim finishes; however, some specialist boards require pre-treatment and some boards are not suitable for skimming.


Boards suitable for skimming

Board Suitable for Skim Pre-Treatment Required
Standard Board Yes No
Viva Cycle Board Yes No
Plank Yes No
Contour Yes No
Base Board Yes No
Vapour Board Yes No
Moisture Board Yes Yes – With a suitable bonding agent
Fire Board Yes No
Fire MR Board Yes Yes – With a suitable bonding agent
Fire Core Board Yes Yes – With a suitable bonding agent
E Board Yes No
dB Board Yes No
Universal Board™ Yes No
Uni MR Board™ Yes Yes – With a suitable bonding agent
LaDura Yes Yes – With a suitable bonding agent
Thermal PIR Yes No
Thermal XP Yes No
Thermal EPS Yes No


Boards not suitable for skimming

Application

Skim plaster can be applied by hand or machine. Always follow the skim plaster manufacturer’s application instructions.

Where PVA is used as the bonding treatment, apply the first coat diluted 5:1, followed by a second coat diluted 3:1, and skim while the surface remains tacky.

Boards must be clean and free from dust, dirt and grease, with sufficient surface key for the plaster thickness being applied.

Allow the skim finish to dry thoroughly before decorating or tiling. When decorating new plaster, follow the paint manufacturer’s instructions.

 

Important

Moisture Board, Uni MR Board, Fire MR Board, Fire Core Board and LaDura require pre-treatment with a suitable bonding agent prior to skimming.

Guidance from BS 8000-8 recommends use of a propriety bonding agent.

Boards should be clean, dry and free from dust, dirt and grease before plaster application.

Allow the skim plaster to dry thoroughly before decorating or tiling.

Follow the paint manufacturer's recommendations for decorating new plaster.

 
 

Tiling

Annex A3: Tiling 

Siniat boards can be tiled in a range of internal environments, from general domestic applications through to areas subject to severe humidity. Board selection should be based on the service environment, tile loading, and system design. Please note, tiles are to be fixed in accordance with BS 5385 and boards are to be installed at maximum 400mm centres in accordance with BS 8000-8.

Maximum tile weight

Board suitability for tiling

Board Normal conditions Low to medium humidity High to severe humidity
Aquaboard™ Yes Yes Yes
Moisture Board Yes Yes No
Fire Moisture Board Yes Yes No
Uni MR Board™ Yes Yes No
LaDura Yes Yes No
Universal Board™ Yes Yes No
Standard Board Yes No No
Viva Cycle Board Yes No No
Fire Board Yes No No
Fire Core Board Yes No No
dB Board Yes No No
E Board Yes No No
Plank Yes No No
Contour Yes No No
Base Board Yes No No
Vapour Board Yes No No

Important

Aquaboard™ is suitable for normal, humid, and severe humidity environments, including swimming pools, spas, wet rooms, and public showers.

Where Aquaboard™ is tiled in severe humidity environments, Siniat Drywall Sealer should be used in accordance with Siniat installation guidance.

Board selection should be appropriate for the intended service environment.

Vertical frame centres for linings and partitions should be determined by both system height and tile weight.

Tile weight, tile size, system height and framing centres should always be checked against the relevant Siniat system guidance.

 
 

Decoration

Sealing prior to decoration

For optimum results, boards should be sealed prior to painting:

Siniat Universal Sealer – Suitable for standard plasterboard surfaces and jointed finishes to improve paint coverage, surface uniformity, and appearance.

Siniat Drywall Sealer – Specifically intended for use with Siniat Aquaboard™ systems, particularly where an appropriate sealed surface is required prior to decoration or tiling in humid or severe humidity environments.

Before decorating

Ensure surfaces and joints are completely dry.

Sand joints smooth where required.

Remove all dust from the surface before applying sealer or paint.

Apply the appropriate sealer before decoration to improve uniformity and paint coverage.

Megadeco boards and joints finished using Siniat Deco Joint Cement do not require sealing before decoration.

Apply paint in accordance with the paint manufacturer's recommendations.

 
 

 

 

Was this article helpful?



Give feedback about this article

Didn't find what you are looking for? Contact our Technical Support

Table of Contents

Related Articles