0845 077 3839

Open: Mon - Fri: 9am - 5pm


Everbuild - 903 Bitumen Trowel Mastic

Availability: In stock

Product Name Price Quantity
£6.30 Per Item (Inc VAT)
£12.19 Per Item (Inc VAT)
£18.58 Per Item (Inc VAT)
All prices include VAT

Quick Overview

Bitumen Trowel Mastic is a trowel applied black heavily filled bituminous compound with added fibres for reinforcement. The product forms a surface skin, but the mass below remains soft to allow for moderate movement. Suitable for sealing and filling holes in mastic asphalt, roofing felt, corrugated iron, metal guttering and downpipes.

Everbuild - 903 Bitumen Trowel Mastic

Additional Information

Product Code eb.903btm
Quick Find Code 007766
Manufacturer Everbuild
Supplier Colour Black
Container Size Multiple
Usage Instructions

BLACK JACK BITUMEN MASTIC is ready for use and should not be thinned. Apply by steel trowel or putty knife.


  • Force the compound into the crack, but finish with a 25mm band at a 3mm thickness running the length of the crack. For large cracks and holes, apply the compound over the area to be treated and embed a closely woven glass fibre membrane into the compound to overlap the crack or hole by 50mm. Allow to dry and then apply a second coat, fully covering the reinforcing membrane.



  • Tighten loose hook bolts and trowel around with mastic. Remove loose screws, re-bed screws and washers in BLACK JACK BITUMEN MASTIC and tighten. Top seal in further mastic and trowel to a smooth finish. If the sheet is cracked, clean and prime with BLACK JACK Bitumen/FLASHING Primer and apply a bandage strip of glass fibre embedded in the mastic. When dry, overcoat with BLACK JACK BITUMEN /FLASHING PRIMER followed by BLACK JACK BITUMEN PAINT. Use the same technique for sealing side and end laps in corrugated sheeting.



  • Point up butt edges of ridge tiles, fillets and slates with BLACK JACK BITUMEN MASTIC.



  • Trowel over cracks and pinholes, where necessary, reinforcing with a woven glass membrane, fully embedded and covered.



  • Re-adhere loose felt using BLACK JACK ROOF FELT ADHESIVE. Apply BLACK JACK BITUMEN MASTIC and overcoat with BLACK JACK ALL WEATHER ROOF COATING. Note: felt must be completely dry before applying the mastic.



  • Tools may be cleaned by using white spirit. Spillage’s should be wiped off surfaces before the primer has set.
Country of Manufacture United Kingdom