UltraScape Pro-Prime 56 x 20KG | Slurry Paving Primer | Covers Approximately 840m² | Free Delivery

'One of the Best Paving Primers on the Market — Independently Tested to >2.20 N/mm² Bond Strength, and Proven on Some of the UK's Most Demanding Projects'

UltraScape Pro-Prime is one of the best slurry paving primers on the market — an excellent example of a product that does exactly what it promises. It creates an exceptionally strong bond between paving and bedding mortar, dramatically reduces the risk of slabs becoming loose or debonding over time, and helps prevent efflorescence and staining appearing on the surface of your paving. It's a product our customers consistently come back to tell us they're delighted with: straightforward to mix, easy to apply, and genuinely effective.

Polymer-modified cementitious slurry primer, independently tested to >2.20 N/mm² adhesion at 28 days, suitable for natural stone, concrete flags, clay pavers and 20mm porcelain — UltraScape Pro-Prime is the professional's choice for patios, pathways, driveways, town centre pedestrian schemes and carriageways.

We're a small, family-run business — I'm Cleo, the owner, with over 25 years in the construction industry working with businesses including Tarmac and Instarmac. I work alongside a team of incredibly knowledgeable and caring individuals, and between us we've seen a lot of paving primers come and go. Pro-Prime is the one we reach for when a contractor needs a reliable, high-performance bond — whether they're laying a domestic patio or working on a major public realm scheme.

If you're a landscaping contractor laying natural stone, concrete, clay pavers or porcelain and want a primer that's been independently tested and proven on some of the UK's most high-profile projects — Pro-Prime is the product we'd confidently recommend. Highly recommended for porcelain in particular, where the non-porous surface means paving will not bond reliably to the mortar bed without a primer. If you're unsure whether you need a primer or which product is right for your project, give us a call.

This deal gives you a full pallet of 56 x 20KG bags of UltraScape Pro-Prime — enough to prime approximately 840m² at 1–2mm thickness, or around 560m² if you're applying at our recommended 3mm. The best value way to buy Pro-Prime, with free delivery included. Ideal for contractors who use Pro-Prime as a matter of course and want to keep a full pallet on hand across a busy season of work.

UltraScape Pro-Prime is a polymer-modified cementitious bonding mortar and slurry primer, specifically formulated to provide exceptional bond between all types of stone surfaces, 20mm porcelain tiles, and UltraScape bedding mortars. Used in conjunction with UltraScape Pro-Bed HS or Eco-Bed, it ensures full and even contact with aggregate particles, promoting adhesion to greater than 2 N/mm² — as required by BS 7533, the industry standard that sets out how paving should be properly installed to last. It is suitable for domestic patios, pathways and driveways, as well as town centre pedestrian schemes, carriageways and large-scale public realm projects.

Pro-Prime has been independently tested to achieve a 28-day adhesion strength of more than 2.20 N/mm² — a figure that reflects genuine, measurable performance rather than a marketing claim. It has been proven on major projects including Grand Central Birmingham, MediaCityUK, Granary Square King's Cross, St Albans Cathedral, and projects for councils including Scarborough, Wakefield and Durham.

Why Contractors Don't Skip the Primer

If you've been in the trade long enough, you'll have seen what happens when primer is skipped — or when the wrong product is used. Loose slabs, rocking pavers, callbacks, and frustrated clients. It's a small part of the job that makes a big difference to the finished result and your reputation.

Not all primers are created for the same job. SBR products are widely used by contractors to improve adhesion, but an SBR-based primer isn't the same as a purpose-designed cementitious paving slurry. In cold weather, SBR-based products can crack and fail — the rubber content becomes brittle as temperatures drop, compromising the bond at exactly the time of year when freeze-thaw conditions are putting the most stress on your installation.

UltraScape Pro-Prime is specifically formulated to bond paving to bedding mortar, achieving an adhesion strength of more than 2.20 N/mm² after 28 days. It's a polymer-modified cementitious bonding mortar — not simply cement and rubber — and that distinction matters when you're specifying for a job that needs to last.

Temperature and freeze-thaw conditions are another reason to consider the primer you specify carefully. Paving primers need to maintain a reliable bond despite repeated exposure to moisture and temperature changes. A purpose-designed cementitious slurry primer such as UltraScape Pro-Prime has been developed specifically for bonding paving elements to bedding mortar and is classified in accordance with BS 7533. Using the right product for the job isn't just good practice — it's the difference between a patio that lasts and one that doesn't.

Paving slabs are not what they used to be. The market is flooded with thinner slabs and cheaper imports, and those slabs are at significantly greater risk of two problems:

• Salt and mineral migration — salts and minerals from the bedding mortar can be drawn up through thinner or more porous slabs, causing efflorescence (white staining) and surface discolouration that your client will be straight on the phone about
• Debonding — without a proper primer coat, slabs can become loose, wobbly and unstable over time. What the industry calls 'debonding', the rest of us call a crooked, rocking, dangerous patio — and a callback you don't need

A primer is also essential for porcelain and dense stone — because these materials are non-porous, standard mortar simply can't grip them reliably on its own. The primer creates the chemical and mechanical bond that holds everything together.

The industry guidance (BS 7533) specifies applying primer at 1–2mm across the full back of each slab. Based on our experience, we'd suggest going to 3mm where you can, and trowelling it on rather than rolling or painting — you get better coverage, better thickness, and a stronger key into the mortar. It's a small extra step that makes a real difference, especially with today's thinner slabs.

Why Choose UltraScape Pro-Prime?

• Exceptional bond strength — independently tested to >2.20 N/mm² adhesion at 28 days, meeting BS 7533 requirements
• Full and even contact — ensures complete coverage with aggregate particles in the bedding mortar for a stronger, more reliable bond
• Meets industry standards — part of UltraScape's BS 7533-compliant system, the benchmark for professional paving in the UK
• Versatile — suitable for all types of natural stone, concrete flags, clay pavers and 20mm porcelain
• Essential for porcelain and dense stone — non-porous materials won't bond reliably to mortar without a primer
• Protects against salt and mineral migration — helps prevent efflorescence and surface staining, particularly important with thinner or imported slabs
• Prevents debonding — reduces the risk of slabs becoming loose, wobbly and unstable, protecting your reputation and eliminating callbacks
• Proven on major projects — Grand Central Birmingham, MediaCityUK, Granary Square King's Cross, St Albans Cathedral and more
• Just add water — supplied pre-blended; simply mix with water on site to create a smooth, workable slurry
• Quick and easy to apply — brush, roller or trowel; workability of 1 hour at 20°C
• NBS Plus registered — for ease of specification by architects and specifiers
• Free delivery — included on this full pallet order
• Coverage: approximately 15m² per 20kg bag at 1–2mm thickness (allow for more if applying at 3mm)

Key Product Information

• This deal: 56 x 20KG bags (full pallet) | approx. 840m² coverage at 1–2mm | free delivery
• Pack size: 20kg reinforced paper bag (pre-blended, just add water)
• Colour: Grey
• Coverage: Approx. 15m² per 20kg bag at 1–2mm thickness
• Yield: 16.9 litres per bag
• Water required: 7 litres per 20kg bag
• Workability: 1 hour at 20°C
• 28-day adhesion strength: >2.20 N/mm² (independently tested)
• Compliance: BS 7533-compliant system | NBS Plus registered
• Storage: Cool, dry, frost-free area between 5°C and 30°C
• Shelf life: 8 months from date of manufacture (unopened)

Preparation

Correct surface preparation is critical to guarantee successful application and durable performance. Remove all debris, ponded water and loose material from the supporting structure or roadbase. Both the roadbase and the paving elements should be cleaned by brushing or washing with water to remove dust, loose material, packaging and any production aids prior to application. All surfaces should be pre-soaked with clean water immediately before applying Pro-Prime.

Mixing

Place 7 litres of clean water in a suitable container. Add the Pro-Prime powder slowly and mix for 3–5 minutes to create a smooth, lump-free slurry. Use immediately — do not allow the mixed slurry to stand before application.

Application

Apply the freshly mixed slurry to the supporting layer or roadbase at 1–2mm thickness immediately before laying the bedding mortar (UltraScape Pro-Bed HS or Eco-Bed). Then apply Pro-Prime to the underside of each paving element at 1–2mm thickness immediately before placing onto the wet mortar bed — or at 3mm if following our recommendation for added protection with thinner or imported slabs. Trowelling gives better coverage and a stronger key than rolling or painting.

Important: the slurry must be fresh and wet when the bedding mortar is laid. Lay the paving while the primer is still active — wet-on-wet placement is essential for a proper bond. Do not allow the primer to dry before placing the slab.

Note: coverage of 15m² per bag is based on 1–2mm. At 3mm you'll use more — factor this into your order.

What Products Make Up the UltraScape Mortar Paving System?

Pro-Prime works as part of UltraScape's complete paving system, which meets BS 7533 — the industry standard for professional paving installation:

• Pro-Prime — this product: slurry primer for bonding paving to the bed
• Eco-Bed / Pro-Bed HS — rapid-strength fine bedding concrete
• Flowpoint — cement-based paving grout applied as a wet slurry. Rapid-set: clean down after 15–30 minutes, walkable after 1 hour, vehicle-ready after 4 hours

Need Some Help?

Download the Pro-Prime technical datasheet (PDF) or see our primer FAQs and article on slurry primers. Or get in touch — we're always happy to help. Call us on 0330 122 1025.

• Brand: Instarmac
• SKU: TPE-PALPROPRMX56
• Weight: 1120.0 kg / 2469.17 lb