5th Mar 2024 -

Condensation poses a persistent problem. If left unchecked, a buildup of moisture can lead to mould, mildew and structural issues. Installing insulated plasterboard serves as an effective method to combat condensation.

Below, we explore the causes of harmful moisture buildup and demonstrate why insulated plasterboard is the best solution. You will learn best practices for installation to optimise condensation resistance.

What is insulated plasterboard?

Insulating plasterboard combines plasterboard with an integrated layer of insulation, enhancing thermal performance and moisture management in buildings. The insulation layer reduces heat loss through walls, ceilings or floors.

It improves energy efficiency and maintains comfortable indoor temperatures. This integrated solution provides thermal insulation and acts as a barrier to moisture penetration. It minimises the risk of condensation forming on the inner surface of the plasterboard. 

Overall, insulated plasterboard offers an effective way to enhance both thermal and moisture control in various construction projects. Learn more about insulated plasterboard with our comprehensive guide.

How does condensation happen?

Water vapour in the air passes invisibly through tiny wall cracks. It builds up and gathers inside. When the air hits cold wall surfaces, the gas changes back into liquid water that sticks as droplets. This buildup is condensation.

Regular plasterboard has lots of microscopic pores and gaps throughout it. Water molecules use these to hold and soak deeper over time. The moisture causes harm by feeding mould, weakens materials and leads to decay.

Standard plasterboard cannot stop condensation moisture from infiltrating behind its surface. The trapped dampness ruins thermal insulation, corrodes framing and will require expensive plasterboard repair work.

How to prevent condensation with insulated plasterboard

When you install insulated plasterboard, it can eliminate the causes of troubling condensation and moisture damage. Here are 6 ways in which insulated plasterboard works to actively resist water vapour issues.

1. Insulates and breaks thermal bridges

The built-in insulation layer inserts a thermal break inside the wall assembly. This lowers conductive heat flow and surface temperatures that lead to condensation while boosting energy efficiency.

2. Creates an integrated moisture barrier

Manufacturers like Kingspan enhance the water resistance in insulated plasterboard's gypsum core using water-repellent additives. Added vapour barrier face paper blocks inward vapour drive, tackling the movement of moisture.

3. Reduces temperature differentials

Reduced heat flow through framing studs means lower temperatures. Lower temperatures create less vapour condensation on cooler wall areas.

4. Blocks humidity

Continuous insulation boards reduce framing joint gaps that leak humid indoor air into moisture-prone walls. This helps create airtight envelopes that transport less water vapour.

5. Fights diffusion effectively

Enhanced plasterboard resists the gradual expansion of water molecules over time. Moisture-blocking insulation enhancements infused directly into the gypsum provide protection instead of relying only on face barriers.

6. Requires no added steps

The manufacturing process adds moisture and insulation enhancements to the plasterboard. This covers multiple forms of condensation resistance in a single component, without the need for added enhancements.

Choose the best insulated plasterboard

Insulated plasterboard offers more than 1 solution for moisture prevention. Whether you need to install thick sheets for exterior walls or thin alternatives for moisture-prone spaces, manufacturers produce insulated boards fine-tuned for purpose.

Insulated plasterboard typeDescriptionBest applicationsInsulated plasterboard thicknesses
Expanded polystyrene (EPS)EPS foam layers lower wall heat flow and temperature swings that draw in vapour. This stable climate gives humidity fewer paths to spread.Interior walls or ceiling plasterboard and partitions in residential buildings.25mm - 40mm
Extruded polystyrene (XPS)Water-resistant XPS foam gives plaster extra sealing power to shut condensation out completely.Exterior walls in colder climates, foundations, below-grade basements and soffits.25mm - 50mm
Rigid polyisocyanurate (PIR)PIR insulation plasterboard is powerful at stopping heat flow, blocking all main condensation routes at once. Moisture cannot form with PIR insulation.High-performance exterior walls or commercial buildings seeking a Building Research Establishment Environmental Assessment Method (BREEAM) certification.25mm - 65mm
Fibreglass-backedFibreglass insulation-backed plasterboard lets some moisture through walls but keeps enough heat to prevent condensing. The thin insulated plasterboard controls moisture flow at safe levels.Interior walls and ceilings in moisture-prone rooms. For example, it can be used as a bathroom plasterboard or in other areas such as a utility room.13mm - 25mm

7 installation tips to tackle moisture

Appropriate installation is important to realise the condensation-resisting potential of insulated plasterboard. By conducting best practice moisture plasterboard measures, you block humidity and boost thermal plasterboards. Below, we advise the following guidelines.

1. Assessing condensation resistance

Make sure properties such as insulated plasterboard U-value and water vapour resistance ratings are sufficient. Higher condensation resistance factor (CRF) scores signal advanced moisture obstruction capabilities.

2. Orienting for optimal protection

Mount with the integrated insulation layer facing the interior room to effectively minimise condensation risks and heating energy losses. 

3. Sealing perimeter gaps

Fill visible cavities around the edges with minimal-expansion polyurethane foam before enclosing. This prevents vapour ingress through framing joist interstices.

4. Offsetting board joints

When you apply multiple layers to a single wall, stagger each joint to obstruct moisture penetration through seams. 

5. Reinforcing seams

Use fibreglass mesh plasterboard tape and joint compound to seal fastener heads and junctions with robust, rigid edges. It stops air leakage through fastener holes or cracks.

6. Plugging wall penetrations

Inject plasterboard sealer into and wrap all mounted boxes, conduits, pipes and wiring with vapour barrier tape. This will plug potential puncture points to stop moisture from entering.

7. Applying vapour barrier coatings

Coat fastened boards with a vapour barrier plasterboard primer upon enclosure. It further reduces vapour diffusion and mitigates risky moisture buildup behind boards.

Can you use the dot and dab method?

The dot and dab technique involves applying adhesive dots or lines onto the wall surface. Plasterboard sheets are firmly on these adhesive points, creating a secure bond. With this method, dot and dab insulated plasterboard can impact condensation and moisture in the following ways.

Limited vapour movement

The plasterboard adhesive used in dot and dab installation creates a barrier behind the insulated plasterboard. It restricts the movement of moisture vapour through the wall assembly. Moisture traps within the wall cavity. 

It increases the likelihood of condensation forming on the inner surface of the plasterboard.

Disrupted vapour barrier

The technique can disrupt the performance of the vapour barrier typically found in insulated plasterboard. Disruption occurs because of the presence of adhesive dots or lines. They can compromise the effectiveness of the vapour barrier.

It creates an increased risk of moisture infiltration and subsequent condensation issues.

Temperature challenges

In areas with significant temperature differences between indoor and outdoor environments, the restricted moisture movement and compromised vapour barrier can heighten condensation problems. 

The thermal insulation properties can also contribute to temperature variations within the wall, further promoting condensation. 

Does bonded plasterboard help to combat condensation?

Bonded plasterboard can contribute to moisture and condensation management to some extent. However, it may not offer the same level of effectiveness as insulated plasterboard. 

The bonding process helps create a secure dry lining attachment of the plasterboard to a substrate like brick or tiles. Plasterboard fixings like a drywall screw or plasterboard wall plugs reduce the likelihood of moisture ingress through gaps or seams. 

Nonetheless, bonded plasterboard typically lacks the additional insulation layer found in insulated plasterboard. This extra layer plays a significant role in regulating temperature and reducing condensation. 

Bonded plasterboard can help mitigate moisture issues to some degree. However, insulated plasterboard is often the preferred choice because of its enhanced thermal insulation properties.

Buy top-notch insulated plasterboard today

At Building Materials Nationwide, we supply cost-effective and high-quality insulated plasterboard engineered to boost thermal efficiency and combat condensation effectively. 

Our selection including straight edge and tapered-edge plasterboard boasts cutting-edge design. All products ensure unparalleled performance in creating vapour control layers for a range of projects. With our innovative solutions, condensation issues become a thing of the past.

Trade customers are welcome to open trade accounts with us. Unlock exclusive benefits and convenience unparalleled in the industry. You gain access to various types of plasterboard, including insulated and moisture-resistant plasterboard, at competitive trade prices. 

As well as speedy UK delivery, our trade account managers streamline transactions and hassle-free procurement. Sign up now or contact the team using the form below for more information. 

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