If you’ve ever used 904 Felt Adhesive, you’ll know it’s one of the go-to solutions in roofing for a reason — it’s tough, versatile, and provides a high-strength bond. At FixTrade.co.uk, we supply EverBuild’s trusted Black Jack 904 Bitumen Roof Felt Adhesive because we know roofers and contractors across the UK rely on its performance in all weather conditions.
But what happens when you need to remove or rework a section bonded with 904 Felt Adhesive? Whether you’re making repairs, replacing damaged felt, or just fixing a misaligned layer, working with bitumen adhesive can be tricky, especially if it’s already cured.
In this article, we’ll walk you through the best practices for safely removing or reworking 904 Felt Adhesive, based on practical trade knowledge and product guidance.
904 Felt Adhesive: What Makes It So Durable?
Before diving into removal techniques, it’s worth understanding what makes 904 Felt Adhesive so effective in the first place.
EverBuild’s 904 is a cold-applied, oxidised bitumen-based adhesive that bonds roofing felt to most common substrates — timber, metal, concrete, and more. It’s ideal for sealing felt laps, bonding chippings to the final layer, or applying gritting.
Its key features include:
• High bond strength
• Tough but flexible finish that adapts with temperature changes
• Resistance to water, alcohol, salts, dilute acids, and alkalis
These properties make it a reliable product, but also a challenging one to reverse once it’s set.
904 Felt Adhesive: Best Practices for Removal and Reworking
1. Know When the 904 Felt Adhesive Has Fully Cured
904 Felt Adhesive hardens as it cools, forming a durable film. Depending on the ambient temperature and thickness of application, it can take up to 24–48 hours to fully cure. If you're looking to rework an area, it’s far easier to do it before it fully sets.
Top tip: If you're working in cooler conditions, you may have a bit more time to adjust placement before the adhesive firms up. In warm weather, it’ll set more quickly, so timing is key.
2. Softening the Adhesive for Removal
If the adhesive has fully cured and you need to remove a bonded section of felt, the most effective method is to soften the bitumen using one of the following techniques:
Heat Application (with Caution)
Using a hot air gun or a roofing torch, carefully heat the bonded area to soften the bitumen layer. Once pliable, use a scraper or flat tool to lift the felt away from the substrate. Be sure to take safety precautions, especially if working on timber or in enclosed spaces.
Important: Never use open flames in confined or flammable areas. Adequate ventilation and fire safety measures are essential.
Bitumen Solvents
For small areas or where heat isn’t an option, bitumen solvent cleaners can help break down the adhesive bond. Apply with care and always follow the safety instructions. You’ll also need time for full evaporation before reapplying any fresh adhesive.
3. Preparing the Surface for Rework or Repair
Once the old felt and adhesive are removed, it’s vital to prepare the surface properly before applying new 904 Felt Adhesive.
• Remove debris – Scrape off residual adhesive, grit, or damaged felt.
• Clean the substrate – Ensure it's dry and free of oil, dirt, or loose materials.
• Prime if needed – On porous or dusty surfaces like concrete, consider using a primer to promote better bonding.
This preparation helps ensure maximum adhesion and a professional finish the second time around.
Reworking 904 Felt Adhesive During Application
If you realise your alignment is slightly off during initial application, there’s still time to adjust — provided the adhesive hasn’t fully cured.
Quick Fix Tips:
• Gently peel back the misaligned felt and reposition.
• Avoid pulling too aggressively — the felt may stretch or tear.
• Smooth out any air bubbles immediately with a felt roller.
• Always press the felt down firmly to re-engage the bond.
If the bond seems weak after adjustment, allow the area to settle, then reapply a thin top-up layer of 904 adhesive at the lap or edge to reinforce the connection.
When Removal Isn't the Best Option
In some cases — especially with older roofs — complete removal might not be feasible. Instead, consider overlaying with new felt, using 904 Felt Adhesive to bond directly to the existing layer (if it’s still in sound condition).
Check compatibility first, and make sure the surface is clean, dry, and structurally intact. This approach saves time, reduces waste, and maintains waterproofing integrity.
FAQs: Common Questions About 904 Felt Adhesive
Can I remove 904 Felt Adhesive without damaging the roof?
Yes — but it requires patience, heat or solvent, and the right tools. Always test a small section before tackling a larger area.
How soon can I reapply 904 Felt Adhesive after removal?
Wait until all solvent has evaporated (if used), the surface is clean and dry, and the substrate is prepped. Then reapply fresh adhesive as needed.
Is 904 Felt Adhesive reusable?
No. Once applied and cured, it can’t be reactivated. You’ll need a fresh application for any reworked or repaired areas.
Why Roofers Choose FixTrade.co.uk for 904 Felt Adhesive
At FixTrade.co.uk, we stock EverBuild’s Black Jack 904 Felt Adhesive because we know it delivers results our trade customers trust. Whether you’re a professional roofer, builder, or an experienced DIYer, you’ll find fast delivery, expert service, and top brands right here.
Need tools, solvents or safety gear to help with your roofing job? We’ve got everything you need under one roof — and we’re here to support your project from start to finish. Contact us for further support.