Cromar Bitumen Felt Adhesive

Cromar is a cold-applied, solvent-based bituminous adhesive designed for bonding multiple layers of roofing felt. Formulated for both ease of use and strong adhesion, this reliable product ensures a durable and lasting bond to bituminous membranes, providing a professional finish on flat roofing systems. Ideal for both residential and commercial applications, this adhesive delivers dependable performance whether you're working with timber, metal, concrete, or asphalt surfaces. Its black finish blends in seamlessly with most roofing materials.

Versatile Uses

This adhesive can be used in a variety of roofing applications, including: Bonding roofing felts to timber, concrete, asphalt, or metal Acting as a lap cement for felt joins Securing chippings to flat roofs It’s also suitable for both first-time roof installations and repairs or refurbishments, making it a go-to product for roofers and DIYers alike.

Surface Preparation and Application

Before applying, ensure the surface is clean and free of dirt, dust, oil, and loose debris. Any signs of algae or fungal growth should be brushed off and treated with a fungicide to prevent regrowth. The adhesive can be applied using a stiff brush, mop, or squeegee. For best results in cold weather, store the container in a warm environment overnight before use. Once applied, the adhesive should be left for 15 to 30 minutes to develop a tacky layer before laying the felt. Carefully press or roll the felt into place to remove any trapped air and ensure a strong bond. On timber roofs, the first felt layer must be nailed down, with additional layers bonded using Cromar adhesive. For porous concrete surfaces, a primer must be used first and allowed to dry thoroughly. Lap joints should be 75mm on the sides and 150mm at the ends. For extra strength, adhesive can also be applied to the underside of the felt at lap areas before pressing down firmly.

Coverage and Sizes

Each litre of Cromar covers approximately 2m², depending on the surface condition and method of application. It is available in 1kg, 2.5kg, 5kg, and 25kg containers, supplied in either plastic or metal formats.

Key Features

Solvent-based, cold-applied bituminous adhesive Excellent bond to timber, metal, concrete, and asphalt Ideal for bonding felt, lap joints, and chippings Easy to apply with brush, mop, or squeegee Provides lasting waterproof adhesion Available in multiple container sizes Black finish for a seamless appearance Approx. coverage: 2m² per litre

Frequently Asked Questions

1. Can I use Cromar in cold weather?

Yes, but for best results, **store the adhesive in a warm room overnight** before use to avoid thickening. This will help maintain smooth and easy application during colder conditions.

2. Do I need to use nails or just adhesive on timber surfaces?

When applying to **timber roofs**, the **first layer of felt must be nailed down**. Successive layers can then be securely bonded using Cromar Roofing Felt Adhesive.

3. What should I do if the concrete surface is porous?

Porous concrete must be **primed first**. Make sure the **primer is completely dry** before applying the first layer of felt to ensure a strong and lasting bond.

At JJ Building Materials, we're committed to supplying quality building products at competitive prices, backed by the service and expertise you'd expect from an established independent merchant. Whether you're a trade professional managing large-scale projects or a homeowner taking on a DIY renovation, we're here to help you find the right products for the job.

As part of the JJ Roofing Supplies Group, we build on decades of experience supplying construction materials across the UK. We've expanded beyond roofing to offer a growing range of building materials, including timber, insulation, landscaping products, plumbing supplies, flooring, doors, bricks, fencing, garden buildings and much more – all available to order online with nationwide delivery.

We work with many of the industry's leading manufacturers to bring you trusted products that meet the highest standards of quality and performance. Our team is passionate about providing excellent customer service, competitive pricing and a straightforward shopping experience from start to finish.

When you shop with JJ Building Materials, you can expect:

• Competitive prices on leading brands and quality products.
• Nationwide delivery across the UK
  
• A constantly expanding range of building and landscaping materials.
  
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Every order is personally reviewed by our experienced team to ensure everything is correct before dispatch. We offer delivery from as little as the next working day on selected products, so please refer to the dark blue Estimated Delivery box above for the expected delivery timeframe for this item.

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Roof Tiles & Fittings:

We recommend ordering an additional 10% of roof tiles to allow for any breakages that may occur during delivery or handling. Roof tiles are naturally fragile, and having a few extra on site helps prevent delays and ensures your roofing project can be completed without interruption.