Frequently Asked Questions

The following is a list of frequently asked questions (FAQ’s).

What is the best method of applying Rubba-Roof liquid roof membrane?

There are 2 recommended methods for applying Rubba-Roof to achieve the minimum thickness of 1 millimetre:-

(a) By Roller

Use a low pile roller and apply a firm, even downward pressure but do not overwork the Rubba-Roof compound. Two passes (orientated at 90 degrees) should be sufficient. Roller application is usually suitable for all surfaces unless they are embedded with chippings or are otherwise rough in texture when a stiff masonry brush or disposable paintbrush can be used. Rubba-Roof supply suitable roller frames, refills and disposable brushes at competitive prices when ordered in conjuction with Rubba-Roof compound and Rubba-Roof Primers.

(b) By Brush

For rough textured surfaces use a disposable paint brush, or stiffish masonry brush, to work the Rubba-Roof compound well in; also to fully wet out corners, overhangs, upstands and similar details. A brush is often the best tool to overcoat mitre cuts and the edges of Rubba-Roof Reinforcing Fleece. Disposable brushes can be ordered as part of your order for Rubba-Roof compound and Rubba-Roof Primers.

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Can I paint liquid rubber straight over the dips & cracks in my roof?

Yes. Rubba-Roof will span cracks and splits of up to about 0.5 mm in a roof surface. We advise the use of Rubba-Roof Reinforcing Fleece for larger cracks. Remember that a split or crack may itself contract and expand with changes in ambient conditions so it is advisable to spend little extra time and materials to ensure the longevity of your roof

Dips. Yes, you can apply Rubba-Roof over dips. Sunken areas will often cause water to ‘pond’ on flat roofs. Ponding or standing water can act as a lens in summer and as an icepack in sub-zero winter conditions; so these areas of flat roofs may well be exposed to thermal shock and an increased range of expansion and contraction. Rubba-Roof compound and Rubba-Roof Reinforcing Fleece may be used to build up ‘dips’ on the surface of a flat roof.

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My roof has expansion joints – can I still use Rubba-Roof?

Yes. Because Rubba-Roof is elastomeric you can overcoat expansion joints. If the joints are in a concrete or asphaltic surface it is advisable to use strips of Rubba-Roof Reinforcing Fleece along the joint lines.

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Will Rubba-Roof repair holes in rigid sheet roofing?

For holes up to about 150 mm x 150 mm in size, Rubba-Roof can be combined with Rubba-Roof Reinforcing Fleece to span the void.

Ensure that you have at least 150 mm of Rubba-Roof Reinforcing Fleece as overlap onto the surfaces around the hole. Take care to fully embed the edges of the Rubba-Roof Reinforcing Fleece into the wet Rubba-Roof compound base coat and that there are no air bubbles.

Warm the tin of Rubba-Roof compound in a bucket of hot water before applying the second coat and apply with care.

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Can I use Rubba-Roof to repair leaking abutments, flashing, valley gutters?

Yes. Rubba-Roof is the ideal solution for waterproofing parapets, flashings, valleys, gutters etc. Use Rubba-Roof Reinforcing Fleece to strengthen the coatings over joints and at any changes in the plane of surfaces; e.g. where the base of a parapet meets a roof surface.

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My garage roof has a porous surface – will Rubba-Roof still work?

Yes. Rubba-Roof will seal micro porous surfaces. Certain substrates may need an initial application of the appropriate Rubba-Roof Primer.

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Will Rubba-Roof adhere to metal surfaces?

Yes. Rubba-Roof will stick to metal. Prepare metal surfaces by rubbing with a wet & dry paper to remove any loose rust and oxidisation, then wash off and leave to dry before applying Rubba-Roof compound and any Rubba-Roof Reinforcing Fleece that may be required. Copper roofs should be acid washed for passivation before the application of Rubba-Roof.

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I’m building an extension with a flat ply wood roof – will Rubba-Roof work?

Yes. Apply a 1 mm thick coat of Rubba-Roof compound to DRY plywood or OSB boards. Use Rubba-Roof Reinforcing Fleece (150 mm wide) along all joints to ensure best performance. Countersink all surface fixings before applying Rubba-Roof compound.

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What type of scrim do you recommend for use on joints and cracks?

Only use Rubba-Roof Reinforcing Fleece which is available in 3 widths, has designed absorption properties, conforms easily to all profiles and is easily cut to size and shape with a sharp pair of scissors.

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My DIY store doesn’t sell reinforcement scrim – do you supply it?

All Rubba-Roof products are are only supplied directly to customers to ensure best value, service, and practical advice.

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Where can I buy clean-up fluid / brush-cleaner for your liquid applied roofing?

The most economical way to purchase Rubba-Roof Cleaning Fluid is as part of a consolidated order for Rubba-Roof compound and associated products. There will be an extra carriage cost if the cleaning Fluid is bought as a separate item.

Please note: Do not use Rubba-Roof Cleaning Fluid to dilute any other Rubba-Roof products.

If you need further information or advice please call 0800 368 7343 or use our contact form for more details.

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