INSTRUCTIONS FOR BUILDING WITH PROMONTA GYPSUM BLOCKS
 

TRANSPORT AND STORAGE

The blocks must be stacked to protect them from water and moisture during transportation and storage. Building work is preferably done once the structure is weathertight.

PREPARATION

After the base floor has been cleaned and set out the required number of profiles should be positioned between floor and soffit. The walls will abut these profiles.

PREPARATION OF THE ADHESIVE

The gypsum Promontine powder is mixed with clean water until homogenous slurry is obtained after about 3 minutes.
The consistency of the slurry must be such that the adhesive is extruded at the joints of the blocks during assembly and the joint thickness is minimal. Adhesive that has become too thick cannot be used.

CONSTRUCTION OF THE PROMONTA WALLS

Where there is a risk of rising damp it is advisable to provide polyethylene sheet beneath the wall.

The first course:

If the base floor surface is too rough the area under the first course can be levelled using mortar, gypsum or a gypsum adhesive mixture. The first course must be laid absolutely level to prevent subsequent vertical joints from opening. The blocks must be laid with the tongued edge at the top and the vertical faces fitted together after they have received the adhesive. The blocks must be pushed firmly together so that the excess adhesive is forced out of the joints. The last block must be sawn to size so that it acts as a keystone. Prior to laying the second course the first course must be checked with a spirit level to ensure it is true and, if required, corrected.

The second and subsequent courses:

The first block must be laid to allow for proper bonding. Sawn surfaces must be free from dust. The blocks must be laid in a tongued and grooved fashion so that the excess adhesive is extruded from the joints on both sides of the wall. The special tongue and groove shape of the Promonta blocks allows the excess adhesive to be forced through the opening. After placing the second and subsequent courses the wall will be checked for flatness.

The top course:

The blocks must be sawn to size so that the joint at the soffit is ca. 15 to 20 mm. The sawn edges should be free of dust.
To reduce wastage it is possible to place the blocks in the top course vertically and to utilise sawn off-cuts in the wall. Once the wall has been checked for plumb and flatness, he will be provisionally fixed at the ceiling.
The excess extruded adhesive is used to fill joints and any imperfections are trowelled smooth.
To ensure the walls and floors are stable, the upper joint is best completed after the total loading of the floor. In this context reference is made to the technical information in document number 132 of the WTCB (BBR), dated September 1980. In order to reduce as far as possible any cracks between the superstructure and the walls, it is advisable to do the plaster works after the walls have been built. If required the gypsum blocks can be fixed to the structure using metal anchors. This should be taken into consideration during the design of the building's functional requirements. It is also possible to use plastic U-profiles having a flexible joint face.
Where gypsum blocks have to be built between columns in concrete or brickwork, the walls must be built ± 15 mm outwards in order to make plastering of the columns in the same surface possible.
Any walls to be built in other than the traditional manner for gypsum blocks, such as freestanding walls, long walls, walls without lateral support, expansion joints, abnormal heights etc, should be properly studied beforehand.

Intersecting walls:

Intersecting walls such as cross-walls, corners, T-junctions etc,
must be bonded every two courses with a minimum of two per storey height.

DOOR FRAMES

Normal timber frames:

The blocks of the first four courses must be laid either exactly to the size of the opening or a few centimetres further.
If the door openings do not continue completely to the soffit, the fifth course must be placed in such a way that the relevant blocks are supported at each end and they must have temporary supports during further building.
Once the adhesive has hardened the door openings are sawn to size. Small lintel heights must be properly catered for. Openings wider than 1,000 mm must be strengthened.

Door assembly sets (e.g. Polynorm types etc):

Special attention is needed to saw the openings to size. It is strongly recommended that the lines of the openings to be executed be carried out after the correct levels have been established.
Possible tolerances should be determined beforehand.

Metal doorframes:

These are usually placed first. Once they have been placed at right angles, checked for plumb, and are level and properly supported, they are anchored in the block wall.
If they are placed afterwards they can still be anchored by filling up the frame with mortar. Special attention should be given to the adhesion between the gypsum blocks and the mortar. Attention should also be given to supporting the opening.

BUILDING IN PIPES AND TECHNICAL FACILITIES IN THE WALLS

Chasing and forming openings in the block walls must be carried out using the correct type of tools, such as chasing machines, drills etc.
Crowbars and other tools causing vibration are forbidden. In any case such chasing and drilling must not affect the structural integrity of the walling. The chases and holes must be filled to within ca. 2 mm of the wall surface with plaster or adhesive mortar.

JUNCTIONS AT THE SOFFIT

Where the superstructure is rigid the top joint can be filled with plaster, which is preferably applied once the final loading of the floor has been achieved. The joint should be free of dust. Where the superstructure is not rigid we refer to the technical information in document number 132 of the WTCB, dated September 1980.
In this case a PVC channel can be used wherein the top course of blocks is located, or a supple top filler joint or a cornice that can be placed afterwards.
A supple top joint filler can consist of a flexible strip or mortar, such as the Elasto WP12. Cracks between the block walls and the superstructure can be visually reduced by the application of a glass fibre sealing strip.

FINISHING AT CORNERS

Metal arris strips should be used to protect the corners. The corners can be slightly hacked away to form a sound base for applying the strips with plaster or adhesive. After it has hardened the corner can be finished properly to give a good surface.

FINISHING OF SURFACES

After all chasing etc has been completed, the joints finished and any imperfections dealt with, the surfaces that are to be left exposed for painting can be given a finishing coat of Promontine or Superpromontine.
This must be done on a dry and dust-free surface.
Surfaces to be tiled or to receive any other type of surface finish do not need to receive this coating.

GUIDANCE FOR PAINTING OR WALLPAPERING

This should be done in accordance with the relevant manufacturer's instructions. Generally a primer coat should be applied prior to painting.

BUILDING AND FINISHING

  • Promonta gypsum blocks should be used as far as possible after the building is glazed and watertight.
  • The gypsum blocks are connected together in a stretcher bond into a continuous whole, using a special gypsum adhesive based on fine gypsum and additives (Promontine).
  • After the wall has been aligned on the weight-bearing floor, a plastic sheet may be used. Rough floors should be levelled on beforehand.
  • The blocks are installed so that the 50 cm sides are vertical, with the tongue facing upwards. As the blocks are fitted together, the gypsum adhesive is forced out of the joints. It can be wiped away and the joints smoothed off later on.
  • The top joint against the ceiling is filled with a mix of plaster and gypsum adhesive, or a flexible joint filler such as Elasto WP12 or PU foam.
  • After openings for electricity and sanitary lines have been drilled, they are sealed with plaster to a depth of ± 2 mm below the surface. This work should be carried out by the relevant specialists.
  • The walls are finished with gypsum adhesive or by a finishing adhesive, Superpromontine.
  • In this way, a smooth wall is obtained, ready for papering or painting. If the walls are tiled or treated with abrasive mortar or a similar material, the gypsum wall should not be sanded.
  • If the gypsum blocks are decorated (e.g. painted or papered), this should be done according to the manufacturer's guidelines.
  • Generally speaking, a primer should be used.
  • Between concrete or brickwork, the walls should protrude ± 1.5 cm to enable plastering to take place in the same plane.
  • Prominent corners should be finished with a fitted corner profile.
  • Measuring: any openings of less than 1m² should not be deducted.
  • Slanting walls should be measured as though they were regular.