Box Gutter Waterproofing

Waterproofing a Box Gutter

Box Gutter Waterproofing is specialized. More than 90% of commercial/industrial Roofs have Box gutters that are designed to redistribute water away from roofs.  Most commercial landlords experience the complete opposite.  Blocked gutters can pool water in gutters causing them to rust and allow water to ingress.  This water leaks destroy masonry compositing  and building structure integrity including.  Leads from Box Gutters are known to destroy product or work environment is under the roof. This can cause thousands of rands damage to building and even interrupt work flow.

Over all the most cost affective long term waterproof solution is our flagship Waterproof Lab Gutter Wrap System using Firestone RubberGard EPDM.  Waterproof Lab has laid 7.5km of gutter in our South African market thus far – with incredibly results and extremely satisfied customers. 

Rain Gutter Wateproofing

The system allows us to save the landlord money.  Some benefitsof Rain Gutter Waterproofing

  • No need to replace the existing gutter – simply line the gutter with Waterproof Lab’s Firestone RubberGard EPDM
  • No seems – Larger rubber sizes (6m x 30m) which allows you to line gutters 30 meters long without a seam
  • Easy to apply – all you need is a silicon roller, Waterproof Lab’s EPDM Rubber
  • Safe to apply – unlike TPO, no torch on, flame required.  The EPDM is adhered to the gutter. 
  • Membrane can mould to the gutter shape easy because of the flexibility of the rubber.
  • Waterproof Lab’s EPDM is totally water resistant and can with stand pooling of water.
  • Waterproof Lab’s EPDM has stretch so it can withstand gutter movement at the joins (in excess of 300%)
  • It most outstanding feature is that is UV resistant and needs no protection layer hence no maintenance cost to the landlord
  • Gutter inlet and outlet pipes are catered for in the flexible system.  Often a big area of water ingress with competitive competitive products
  • The system allows for aluminium termination bars (with allow nails and watermastic) should the EPDM need to be secured against an up stand wall or similar. 
  • The system allows for wooden gutters too. 
  • Damage could easily be repaired should it be necessary. 
  • Waterproof Lab offers training and distributes customised sizes to the Landlord, architect, engineer and contractor


Tygervalley Centre

Waterproof Lab was contracted to seal a leaking box gutter above one of Tygervalley Centre’s anchor tenants. The failed waterproofing was removed and replaced with EPDM - a strong advantage of using this waterproofing system in this application was the waterproof membrane’s high UV resistance to the strong African sun and the fact that we could terminate the membrane against the vertical wall of the parapet with aluminium termination bar.
Box gutters

Frequently Asked Questions


Firestone RubberGard EPDM would be highly recommended as the best advice to solve your problem. The beauty about using this system is that there is NO pap and lap.  The membrane is factory cured and we adhere a rubber membrane all alongside the upstand and length of your gutter.  Most time we will seal an entire 30m length gutter with rubber membrane and no seems hence reducing the risk of membrane join leaks (See below for application advice);

 Most waterproofing systems on the market do not cater for the African Sun high UV.  Also most systems cannot take pooling water. Firestone RubberGard EPDM meets both criterias making it a most superior waterproofing system for your Roof Gutter.  Please see explanation, below;

EPDM is a strong, highly flexible rubber membrane, with minimal seams (joints) which is designed as a reliable medium for sealing gutters & many other waterproofing problems. Its African Sub UV friendly and not protection is needed after application to protect it from the UV.  The long seemless RubberGard installation poses less risk for wateri ingress through incorrect seeming done by contractors hence minimising the risk of leaks.   Once applied it is known to outlive the roof and the gutter. (See methodology below);

In some instances this might be necessary. However, in most cases depending we recommend unscrewing the roof sheets from the purlins and tucking the Waterproof Lab RubberGard membrane under and refastening the screws.  This eliminates the necessity to go through the expensive procedure of removing your roof and gutter.  In short Waterproof Lab’s Firestone RubberGard membrane will save you thousands if not hundreds of thousands of rands in a case of a big roof.

This is a simple procedure, which is covered In detail in the methodology below;  Also see the videos on Waterproof Lab’s website

Because EPDM comes in rolls measuring 6m wide x 30m long, it is possible to cut a piece to exactly fit your gutter, thus eliminating the necessity for joints. (see methodology below);

Your question has been addressed in full, in the methodology below but yes, the membrane can breach rusty holes;

Yes.  This system is designed to save the landlord money.  The product is world class and backed by one the the strongest internation brands in the industry, namely Firestone Building Products The methodology below is tailor made for your solution.


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