The role of the Gypsum Products Development Association (GPDA) is to develop and encourage the understanding of gypsum based building materials and systems.
Technical Literature
- Compatibility Statement
- Cracking noises from residential timber floor structures constructed with engineered ‘I’ joists
- Fire Performance Statement
- Gypsum Dust
- Decoration and Discolouration of Plasterboard
- Guidance on limiting maximum heights drywall partitions and linings
- Mechanical statement of lift shaft
- Use and limitations of drywall specifications and standard details
- Checklist for product compliance with Construction Products Regulations (CPR)
- Creaking in tall residential towers in high winds
- Firestopping Guide
- Fire Labelling
Technical Advice
Action | Likely consequences (results) |
Don’t leave boards outside without covers | Boards may get damaged |
Don’t store in the open | Boards will absorb moisture if covers have been damaged, removed or blown off, risking deformation, decoration problems, delay in the jointing process and/or mould growth |
Don’t place pallets on uneven ground | Boards may deform |
Don’t place pallets or board on wet ground | Board may absorb moisture |
Don’t use less than 5 bearers under a pack if not on a wooden pallet | Boards may deflect |
Don’t use damaged boards | Broken edges & cracked cores are unacceptable |
Action | Likely consequences (results) |
Don’t forget to check board weight | HSE max is 25kg per person. If you exceed this weight |
Do lay boards flat | Vertical boards may bend and take on a set deflection |
Don’t single-handedly try to carry two boards | Injury could result |
Don’t forget to carry board on edge | Boards may bend if carried horizontally. This may lead to |
Don’t use wet board | It may lose its structural integrity |
Don’t slide boards off the pack if the paper is damaged | You will get paper ‘roll-ups’ |
Don’t damage corners and edges when manoeuvring around | Can’t use damaged boards. If damaged cut down to next |
Action | Likely consequences (results) |
Do fix boards according to plasterboard manufacturer’s recommendations | |
Do follow plasterboard manufacturer’s guidelines regarding minimum timber stud/joist dimensions |
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Do stagger the boards on opposite sides | If the boards are not staggered the system may be weakened with reduced fire resistance |
Don’t fix boards if they are wet | Use of wet board is not recommended (staining, mould or /and sagging may occur) |
Don’t fix boards if plaster core is cracked | Affects fire rating |
Don’t use boards with broken corners | End cracks in joints |
Don’t fix boards to wet timbers | Board joints may crack and nails pop as timber shrinks |
Don’t screw or nail board to narrow timbers < 38mm | Manufacturer’s recommendations cannot be met |
Don’t forget that screws are better than nails and you need less of them (use screws where possible) | Nail pops are a serious maintenance item |
Do use a drill with gauge depth adjustment to fix drywall screws | A drywall screw gun is preferable, otherwise screws may fracture the paper liner and sink below the surface rendering them ineffective |
Don’t restrict ventilation (ventilate rooms) | Moisture, if not free to escape, may cause condensation and may be absorbed by boards |
Don’t use a blunt Stanley knife | You get jagged edges to the board and there is more risk of injury |
Don’t cut service holes with a board knife and hammer | Back of board may have damaged the paper liner. Use a pad saw. |
Do use vapour resistant board in a location that is likely to have high moisture (bathroom/kitchen) | Avoids moisture damage |
Don’t attempt to wet plaster moisture resistant board | Such board is designed to resist moisture and the plaster may not bond |
Don’t install wallboard onto misaligned timber framing | You may get a ridged joint |
Don’t use nails to fix ceiling boards to engineered joists eg TJI, JJI, type | You may loosen the floor boards above causing them to creak |
Action | Likely consequences (results) |
Don’t ‘knock up’ the bonding compound with more water when it starts to set | It may not bond |
Don’t use small dabs far apart. Do follow manufacturer’s recommendations on dab size and location | Incorrectly fitted board |
Don’t direct bond onto wet masonry | Dab will dry out into background instead of through board and pattern staining may occur |
Do use continuous dabs joined up where specified | Otherwise ‘chimney’ effect will reduce thermal insulation and sound insulation resulting in the need for a cavity barrier |
Don’t bridge the joints with dabs | Joints may crack |
Don’t use vapour control (foil backed) boards with plaster bonding dabs | |
Don’t attempt to dab plasterboards if the background material is in doubt | You may get bond failure |
Action | Likely consequences (results) |
Do use nailable plugs in accordance with manufacturer’s recommendations if you are fixing by direct bond method | Board may delaminate in a fire, causing plasterboard to fall over and block an access route. |
Do fill the gap behind the skirting | Essential for good sound insulation and cavity barrier. Failing to fill the gap will result in thermal loss. |
Don’t fix these boards with dabs if they are bowed | Linings will be out of range / plumb |
Don’t use thermal boards on ceilings unless phenolic | Appropriate Building Regulations regarding surface classification of both sides of ceiling boards should be followed |
Do check condensation risk, as you may need vapour check layer | Otherwise, condensation problems may result |
Action | Likely consequences (results) |
Do adjust bracket length so that the finished lining will be plumbed and ranged |
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Do use protective gloves when handling metal | Minimise the risk of injury |
Don’t go wider than 800mm with brackets (unless brackets are adjustable) | Boards may flex too much |
Do screw boards to bottom track. Do fix boards to framing in accordance with manufacturer’s recommendations. | Joints may crack and sound insulation may be reduced |
Don’t forget that this system may need a vapour control plasterboard lining in some circumstances |
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Do use a DPC if used on new concrete | Chemical alkaline attack to zinc under J track. Also moisture may travel up the plasterboard core |
Don’t forget that with ‘I’ studs you may need special drywall screws | Normal S point screws will not penetrate |
Don’t forget that if you have an uneven floor surface you need to provide a timber sole plate prior to installation of the floor track | Floor track may bow if not adequately supported along its length |
Don’t forget that when using mineral wool with this system, the wool goes behind the metal but should not be in contact with the wall | Moisture may track from wall back into wool |
Action | Likely consequences (results) |
Don’t mix and match boards, studs, accessories and finishings from different manufacturers | No warranty, no performance guarantee |
Do read manufacturers specifications first |
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Do use an acoustic sealant under tracks, where specified | Leakage/optimum acoustic performance |
Do provide a timber sole plate if you have uneven floor surfaces | Floor track may bow if not adequately supported along its length |
Do provide a DPC over new concrete floors | Without a DPC, you may get corrosion of zinc. DPC aims to avoid moisture in the new concrete from travelling up plasterboard core. |
Do use protective gloves when handling metal | Minimises the risk of injury |
Do use the appropriate deep (or extra deep) leg track where high partitions and / or deflection heads are specified. Obtain manufacturer’s advice if necessary |
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Do use the correct width, gauge and spacing of stud to suit the height | Partition will not be strong enough if incorrect framing members are used |
Don’t use blunt tin snips with thin metals | Metal will have corners like ‘fish hooks’ and you risk personal injury |
Don’t provide less then 600mm overlap when splicing studs | Joint will be too weak |
Don’t start screwing boards near return flange side | Screws may push stud away and cause a step in the joint |
Do back support horizontal board joints with a suitable section | Joint can crack and give reduced fire resistance |
Don’t have vertical joints above each side of door opening | Joints may crack when door slams |
Don’t screw boards to top track if there is a deflection head | Deflection may be restricted |
Don’t forget that there are special details for movement joints and service baffles | Otherwise technical performance of partition will not be maintained |
Do screw boards to resilient bars ensuring the screw does not penetrate through to studs | Otherwise, acoustic insulation will be short circuited |
Do comply with all relevant guidelines / legislation relating to electrical installations and use of electrical tools |
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Don’t forget special detail at T junctions when fixing acoustic partitions | Sound insulation expected will not be achieved |
Action | Likely consequences (results) |
Do follow manufacturer’s advice regarding board thickness, joist size and spacing, noggings, suspended ceiling framework |
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Do use protective gloves when handling metal | Avoids the risk of injury |
Do use correct screw type and screw length as specified by the manufacturer | Avoids risk of loosening of the ceiling boards |
Don’t fix boards direct to ceiling joists if they are not level | Joints may crack and nails may pop, use metal furrings or counter battens instead |
Don’t use plaster skim or undercoat more than 6mm thick on ceilings | Boards may get too wet, core may soften and ceiling could fall down |
Do start board fixing from the centre of the board | Otherwise unsupported ends may sag down and cause board core to crack |
Don’t use single layer 9.5mm wallboards if fire rating is required | No fire rating with these boards |
Don’t fix suspended ceiling hangers to concrete soffits with shot fired pins | Ceiling may fall down |
Don’t overload ceilings with services – follow manufacturers recommendations. Contact the manufacturer for advice. | Ceiling may fall down |
Don’t use heated ceiling panels and membranes behind MF ceilings | Joints may crack and board may calcine, depending on temperature |
Action | Likely consequences (results) |
Don’t start jointing and finishing if the temperature is below 4°C | Joint cements may not dry and set |
Do address any protruding nails or screws prior to the jointing process but don’t sand nail and screw heads (may give a rust spot) |
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Do use plasterboard manufacturer’s proprietary drywall primers | These have been specially developed to achieve the best finish |
Do apply finish coat plaster to the prepared face. This face has been prepared to accept finish coat plaster. Do consult the plasterboard manufacturer if applying an undercoat plaster to a plasterboard |
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Don’t mix and match fillers and finishes from different manufacturers | There might be a compatibility problem |
Don’t use watered down emulsion paint as a primer or so called ‘mist coat’ | It puts too much water into the paper & core and can cause staining |
Don’t fill and tape with air drying compounds then finish with setting compounds | Tapes may peel off. Bedding compound cannot dry out |
Don’t use fibreglass tape if you wish to reduce the risk of hairline cracks. Do use paper tape rather than fibre mesh. | Fibre tape does not bond strongly to board. Paper tape achieves a stronger joint |
Do box out as wide as you can then sand and leave to dry fully before painters come | Joints may shrink and become visible |
Don’t think that you have to use square edge boards for skimming and texturing | Joints between TE boards are generally stronger |
Don’t use air drying compounds for corner beads | They will not stick |
Action | Likely consequences (results) |
Do use a drywall primer before painting | Suction of joint and paper liner will not be equalised without a drywall primer |
Do use drywall sealer if the wall is to receive wallpaper | Without sealer, wallpaper cannot later be removed without damaging board liner paper |
Action | Likely consequences (results) |
Don’t try to repair boards which have been subjected to flood damage | Even when dried out the boards may have deteriorated. Use new boards |
Don’t try to repair boards where there has been fire or smoke damage | Board will have been subjected excessive heat. Black soot will not wash off. Use new boards |
Don’t try to straighten or level up sagging ceilings where there has been high humidity | Boards will have taken on ‘set’ and cannot be flattened. Remove and fit new boards |
Don’t repair holes by plastering with scrim tape over hole | Hole area may be too weak. You should use a backer board bigger than the hole |
Don’t try to repair damage to fire rated drywall systems | Fire rating cannot be achieved from damaged boards. Use new boards |
Don’t re-use nails and screws if they have been in wetted area, even if they look OK | They may rust or corrode later. Use new screws or nails |
Don’t start repair work after flood or fire damage until the building is absolutely dry | You may get sagging boards, nail pops, mildew and rusting fixings |
Don’t try to use more layers of emulsion point if the boards show signs of striping and staining | Staining may still come through. You should use an oil based alkali resistant primer |