On most construction sites, building chemicals and adhesives don’t get much attention, but they’re vital to the strength, durability, and finish of a job. Whether you're bonding materials, improving mortar performance, sealing gaps, or preparing surfaces, these products often make the difference between a solid build and one prone to failure or early maintenance.
According to the Construction Products Association (CPA), specialist construction chemicals are a key part of the £60 billion UK building products market, and are essential for meeting today’s performance standards, particularly in weatherproofing, energy efficiency, and durability across modern builds.
In this guide, we’ll explain the key types of building chemicals and adhesives you'll encounter on site, from foams and silicones to primers and plasticisers, along with when to use them and how to get the best results. Whether you're a site manager, builder, or tradesperson, this is your practical breakdown of what to use, where, and why it matters.
Sealants and Silicones: Filling Gaps and Finishing Right
Sealants and silicones are essential for finishing work across a wide range of construction tasks, from internal bathrooms to external cladding. Used in both structural and decorative applications, the right sealant ensures that movement, moisture, or temperature changes don’t lead to cracks or failures.
There are several types of sealants used in the trade:
Acrylic sealants: best suited for internal use around skirting boards, architraves, bathrooms, and wet rooms. Acrylic sealants are paintable and cost-effective, but not always waterproof.
Sanitary silicones: contain mould-resistant additives, ideal for kitchens, bathrooms and wetrooms. Sanitary silicones are flexible and perform well in humid environments.
High-performance silicones: used externally around windows, doors, and facades. These offer better adhesion and weather resistance, especially on non-porous surfaces like glass, PVC, and metal.
Good quality sealants help prevent water ingress, improve insulation, and ensure a clean, professional finish. The UK silicone sealant market continues to grow, driven by demand for airtightness in energy-efficient builds and robust weather protection in exposed locations.
For trade jobs, always check product specifications for compatibility with the materials you’re working with – some sealants won’t bond correctly to certain plastics, metals, or damp surfaces.
Construction Adhesives: Strong Bonds Without the Screws
Construction adhesives are designed to provide strong, long-lasting bonds between a wide variety of materials, including timber, brick, plasterboard, metal, and plastics. These adhesives save time on site, reduce visible fixings, and often allow for quicker installation. For internal and external work, they help secure trims, skirting boards, stair nosings, panels, battens, and more.
Here are some of the most common types of construction adhesives:
Grab adhesives: Available in solvent-based or solvent-free formulas. Solvent-based versions typically offer faster tack and stronger initial hold, while solvent-free types are more environmentally friendly and suitable for sensitive areas.
Hybrid polymer adhesives: These combine the flexibility of sealants with the strength of adhesives. They cure fast, bond to almost any surface (even damp ones), and can handle movement and vibration.
Epoxy adhesives: Ideal for heavy-duty bonding on concrete, masonry, and metals. Epoxies are usually two-part systems and deliver exceptional durability and chemical resistance.
Always check the working time, cure speed, and compatibility with your substrate to avoid adhesion failures – especially in cold, wet, or dusty conditions.
PU Foam and Expanding Foams: Quick Fills and Airtight Seals
Polyurethane (PU) foam, more commonly known as expanding foam, is a trade essential for sealing gaps, insulating cavities, and fixing awkward spaces where traditional materials just don’t fit.
There are two main types of expanding foam used on-site:
Standard PU foam: used for general filling, insulating, and fixing jobs. It expands on application and sets firm within minutes. Best for use in dry conditions on clean, dust-free surfaces.
Fire-rated PU foam: provides fire resistance for up to 4 hours, depending on the product. Used around fire doors, service penetrations, and between building elements to maintain fire compartmentation.
Foams are also available in low-expansion formats for more controlled applications, and specialist acoustic foams help reduce sound transmission in partition walls and floors. One of the biggest benefits of PU foam is time saving. It can replace traditional methods like mortar packing or insulation batts in smaller voids and cures quickly, often ready to trim, plaster, or paint over within an hour.
Primers and Bonding Agents: Getting Surfaces Ready to Perform
Primers and bonding agents are essential for preparing surfaces before applying finishes like plaster, render, adhesive, or screed. They help improve adhesion, reduce dusting, seal porous backgrounds, and create a stable, consistent surface for the next layer to bond to.
Some of the most commonly used primers and bonding agents include:
PVA (Polyvinyl Acetate): a general-purpose primer and sealer often used on internal walls and ceilings before plastering. It helps reduce suction and dust, but isn’t suitable for wet or external environments.
SBR (Styrene-Butadiene Rubber): a more robust bonding agent ideal for external work, tiling, rendering, or use in damp conditions.
Universal primers: water-based or acrylic solutions suitable for sealing porous surfaces, reducing absorbency, and promoting adhesion for tile adhesives, levelling compounds, or screed.
Bonding failures remain one of the most common reasons for plaster delamination and tile lifting, particularly when surface prep is rushed or skipped entirely. Using the right primer or bonding agent is a simple, cost-effective way to avoid callbacks and rework.
For best results, always follow the manufacturer's instructions for dilution ratios, drying times, and compatibility with the finish materials you plan to apply.
Cleaners and Surface Treatments: The Finishing Touch
Once the main construction work is done, it’s easy to overlook the final stage: clean-up. But leaving a site clean and presentable is just as important as getting the structure right.
When cleaning after a construction project, consider these products:
Mortar stain removers and brick acid: effective for removing cement splashes, efflorescence, and stubborn site grime from brick, stone, and concrete. These are acidic solutions and should always be used with care.
Multi-purpose construction cleaners: ideal for surfaces like UPVC, tools, and equipment. These help remove grease, sealant residue, and adhesives.
Patio and paving cleaners: used post-installation to restore the appearance of external surfaces, particularly after pointing or jointing work.
Always consider PPE when working with cleaning chemicals – this includes gloves, eye protection, and adequate ventilation. Some cleaners can be corrosive and may damage finishes if not diluted or rinsed properly, so it’s essential to follow usage instructions.
Choosing the Best Product and Finishing the Job Right
While they may not be the most eye-catching items on site, building chemicals and adhesives are essential to the quality and success of your work. From bonding and sealing to preparing and protecting, these products help ensure strength, longevity, and a professional finish across every stage of a project.
Understanding the purpose of each type, whether it’s a flexible sealant, a reliable PU foam, or a bonding primer, can save time, prevent failures, and reduce costly callbacks. Used correctly, they make jobs quicker, cleaner, and more resilient.
MP Moran stocks a full range of trusted, trade-quality building chemicals and adhesives, alongside advice to help you choose the right one. Whether you’re sealing, sticking, priming or cleaning, you’ll find everything you need in branch or online.
Explore our full range of sealants and adhesives or speak to your local branch for expert guidance. Open a Trade Account for exclusive benefits and streamlined purchasing.