Thermoflex

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Introduction
Product background
Properties
Concrete roof decks
Planters and flower boxes
Under screed or tiles
Water retaining structures
Vehicular trafficable areas
Reference list


Thermoflexsystem

TORCH-ON BITUMEN MEMBRANE WATERPROOFING

Darachem has been in the business of manufacturing modified bituminous compounds for waterproofing since 1975

Thermoflex has been in production since 1982 and has been developed specifically for South African conditions, which on the highveld are extreme. Assistance in product evaluation has been provided by the C.S.I.R.

Thermoflex consists of a 180 gram heat set chemically bonded (double reinforced) needle punched polyester geo fabric, manufactured in an ISO 9000 certified plant. This comprises the“ Carrier “ or core of the product. Impregnated into this is S.A.B.S. certified bitumen, which is modified with A.P.P. (attactic polypropylene) and various other components, which provide flexibility and ultra violet light resistance. The weathering surface is treated with an inert silica, which provides a key for adhesion of topcoats, should aesthetics require. The under surface comprises a heat sensitive polymer film which melts at the correct temperature during application.

Over three million square meters of THERMOFLEX has been specified and is successfully performing on roofs throughout Africa. The product is fully backed by our manufacturers guarantee and has a life expectancy of in excess of twenty years.

Full literature and reference to projects are provided in this brochure 

Introduction

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Thermoflex
Waterproofingsystem

Product Background

Bitumen remains the most important base material for waterproofing today, this despite the fact that dozens of “miracle” new products have come on to the market. Bitumen is inexpensive, inherently waterproof, durable, has excellent adhesive properties and is non toxic. Examples of five thousand year old applications of bitumen exist in the middle east. No other system has this track record as a waterproofing agent. Unmodified bitumen has the disadvantage of being brittle at low temperatures and soft or liquid at high temperatures. Flexibility  and flow resistance over a temperature range of  zero to ninety five degree centigrade is a prerequisite for South African conditions.
In depth research and development over a nine year period has led to the development of THERMOFLEX A P. ( Atactic polypropylene ) modified torch-on membrane. Specifically developed for harsh African conditions THERMOFLEX A P offers the following.
Vastly improved elasticity capable of accommodating thermal movements of roofs. ( Particularly required with the increase in the use of thermally insulated roof decks. )
Improved flexibility at low temperatures, enabling laying in cold weather.
Improved strength, allowing a single ply application.
Improved resistance at application temperatures, to permanent deformation, puncture and tear. Giving good “walk on” properties during and after application.
Greater capacity to bridge movements of cracks and joints in the substrate and better fatigue resistance.

Why use a ready made Torch-On Membrane ?

Liquid applied waterproofing systems will always find applications. They do however have inherent disadvantages. Due to unevenness in substrates it is virtually impossible for the contractor to apply the product uniformly. Some areas will have product in excess of and others less than specification. Invariably those areas under applied will be weak and problems may occur.
Unscrupulous contractors may deliberately under apply product without necessarily changing the finished appearance of the roof.
A ready made membrane eliminates these pitfalls. THERMOFLEX  A P is a mechanically produced product of uniform thickness. 

Backgroud

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Thermoflex
waterproofingsystem

Properties

Physical Properties	Colour	Black
	Total Solids	100%
	Specific Gravity	1.3 – 1.4
	Water Vapor Permeability	Impermeable
	Chemical Resistance	Resistant to mild acids and alkali solutions. Not resistant to hydro-carbon solvents, diesel
	Slump Resistance	Will not slump on a                     vertical surface at 95 c
	Penetration(100g/5s/70c)	50-60
	Cold Flexibility(20mm mandrel)	< 5c°
	Elongation @ 25c	>25%
	Tensile Strength	>900 N/5cm
	Tear Resistance	>300 N
Applications	Concrete Roof Decks	See application sheet 1
	Planters and Flower Boxes	See application sheet 2
	Under Screed or Tiles	See application sheet 3
	Water Retaining Structures	See application sheet 4
	Vehicular Traffic Areas	See application sheet 5
Description	Thermoflex AP is a torch on APP modified bitumen Membrane, available in 3.5, 4.5, and 6 kg/m sq grades in 10m roll lengths 1m wide
Construction	The membrane  consists of a 10 micron LDPE plastic to prevent blocking the adhesive layer of modified bitumen a stabilized 180 gm  needle punch polyester carrier A weathering layer of modified bitumen coated with silica to prevent blocking and supply a surface key for decorative finishing coatings.

Physical Properties

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Thermoflexsystem

THERMOFLEX APPLICATION SHEET NO. 1
WATERPROOFING OF CONCRETE ROOF DECKS

Discussion

Concrete roof decks normally consist of a slab screeded to a fall with a sand cement mixture. In the case of a new structure, a minimum of 2 rain free weeks drying period is required before waterproofing. In the case of an old roof, existing waterproofing should be removed and a drying period consistent with the amount of water absorbed allowed. As this is often difficult to estimate it is suggested that either our technical department is consulted or vent pipes ( 10 sq. m of roof area ) are provided to  prevent bubbling due to trapped water vapour.

Surface Preparation

All forms of surface contamination must be removed to ensure a clean smooth surface free of any loose material, or any other barrier to adhesion. Cracks or voids must be filled using HYPERCRETE  (modified cementitious material ) and allowed to cure for a least 24 hours. Should the parapets be rough a HYPERCRETE slurry should be applied to the area to receive the flashing. Fullbore covers should be removed to facilitate “dressing in” the waterproofing. It is recommended that the fullbores be checked to ensure they are functioning correctly.
Finally, an assessment should be made, as to what extent if any ponding is likely to occur. Standing water present, in excess of 5 mm is considered excessive. All low areas should be levelled with a topping of HYPERCRETE. Waterproofing over expansion joints should be laid on top of a PVC slip-sheet once the joint has been sealed. Under no circumstances should the waterproofing be laid directly over the expansion joint.

Application

 Apply a thin uniform coating of THERMOFLEX PRIMER by means of a paint roller to the entire area including the parapets. Coverage will depend on the porosity of the substrate, but 6 sqm/ L of primer should be obtained. Allow a drying period of 3 hours. Lay up the entire roof area allowing 75 mm overlap on side joints 100 mm on end joints and at least 200 mm for turn-ups at the parapets. Joints can now be torched together and all edges sealed with a heated trowel.

Flashings

It is recommended that the THERMOFLEX be turned up the parapets 150mm. A DARAFLEX flashing strip of 300mm should overlap the turn-up in such a manner that 100mm of its width be on the horizontal plane and 200mm on the vertical. (See DARAFLEX data sheet)

Finish coat   

A choice of REFLECT (Bitumenous Aluminium Paint) which is highly reflective or DARACRYL Acrylic (available in colours ) must be applied. If the acrylic topcoat is chosen, a pastel shade is recommended to improve reflection and reduce surface temperature.

Application        

Before applying REFLECT ensure that the product has been well stirred. The product should be applied with a paint roller at an application rate of 5 sqm/L. NOTE: The paint should be stirred at regular intervals to ensure a consistent appearance. The coating must not be applied under wet conditions or to a moist surface. REFLECT is a solvent based material, is highly flammable and should only be applied in a well ventilated area.
When applying DARACRYL to a very hot THERMOFLEX surface a mixture of one third paint to two thirds water should first be applied as a primer coat. Allow 30 minutes drying time before applying DARACRYL with a paint roller, at an application rate of 3sqm/L. DARACRYL only develops full water resistance after a few days. It is therefore essential that it is not exposed to excessive ponding during this period. 

Maintenance    

This system is recommended for occasional light foot traffic. The products life expectancy can be significantly improved by re-coating the roof every 2-3 years.

Concrete Roof Decks

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Thermoflexsystem

THERMOFLEX APPLICATION SHEET N0.2
WATERPROOFING OF PLANTERS AND FLOWER BOXES

Discussion

The requirements of a waterproofing system for the above are: Resistance to constant dampness. Resistance to root penetration. A degree of mechanical resistance, as spades and gardening forks are used in the course of garden maintenance. Drainage stones are normally placed beneath the soil and separated by a layer of geo-fabric

Surface Preparation

All forms of surface contamination must be removed to ensure a smooth surface, free of any loose material or any other barrier to adhesion. Cracks or voids in the surface must be made good using HYPERCRETE, (modified cementitious material) and allowed to cure for a minimum of 24 hours. Should the planter box consist of a bricked structure, the whole internal area can be levelled using HYPERCRETE

Application

By means of brush or roller apply a thin uniform coating of THERMOFLEX PRIMER to the entire surface to be waterproofed. Observe fire precautions. Allow a 3 hour drying period and “lay up” the area with  THERMOFLEX. Ensure a minimum of 75mm for overlaps. Fold THERMOFLEX back from the vertical surfaces and burn off the plastic backing sheet. Place the heated THERMOFLEX onto the surface ensuring complete contact. Using a trowel lift up the membrane at the overlaps and torch, running along all the joints. Press the heated surfaces together. All edges can now be smoothed by means of a heated trowel 

Finish Coat Application

In order to provide mechanical protection, a HYPERCRETE cementitious finish is recommended. The natural colour is cement grey but by means of incorporating pigments a dark green, brown or black colour can be achieved.
Prepare the HYPERCRETE slurry in the following manner.
Add ± 10 lt of water to 1 bag of OP. cement. Trowel the mixture to a uniform consistency and whilst mixing add 15 Lt of HYPERCRETE. A consistent lump-free slurry is thus prepared.

Ensure that the THERMOFLEX is clean and free of any barrier to adhesion.

Apply by means of brush or roller HYPERCRETE slurry to the THERMOFLEX at a rate of 1sqm /L and immediately embed SPB100 Geo-fabric into the wet product. Allowing a 30 minute drying period between coats and apply a further 2 applications of HYPERCRETE slurry at the rate of .75 Lt / m sq.
N.B. The completed system should be protected from rain for a period of 48 hours at 25 deg. C at RH 65 % A further 24 hour period should be allowed before the planter may be filled.

The completed system is maintenance free providing reasonable care is taken
during gardening operations.

Planters and Flower boxes

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Thermoflexsystem

THERMOFLEX APPLICATION SHEET NO. 3
WATERPROOFING UNDER SCREED OR TILES

Discussion

Shower areas, balconies etc. often require a waterproofing membrane. THERMOFLEX has successfully been used for this application.

Surface Preparation

All forms of surface contamination must be removed to ensure a smooth surface, free of any loose material, or any other barrier to adhesion. Cracks or voids in the surface must be filled using HYPERCRETE (modified cementitious material) and allowed to cure for a minimum of 24 hours. Should the parapets be rough a HYPERCRETE slurry should be applied over the area which is to receive the flashing. Fullbore covers should be removed to facilitate “dressing in” the waterproofing. It is recom­mended that the full-bores be checked to ensure that they function correctly. Finally an assesment should be made as to what extent, if any, ponding is likely to occur. Standing water present after rain and run-off in excess of 5mm in depth is considered as excessive. A topping of HYPERCRETE in such areas is recommended. Expansion joints (if present) should be sealed and a PVC slip sheet placed. In no circumstances should the waterproofing be laid directly over the expansion joint.

Application

By means of brush or roller apply a thin uniform coating of THERMOFLEX PRIMER to the entire surface to be waterproofed at a rate of 6sqm/L. Observe fire precaution. Allow 3 hour drying period and “lay up” the area with the THERMOFLEX . Ensure a minimum of 75mm for overlaps. Fold THERMOFLEX back from the vertical surfaces and torch off the plastic backing sheet. Place the heated THERMOFLEX onto the surface ensuring complete contact. Using a trowel lift up the membrane at the overlaps and torch, running along all the joints. Press the heated surfaces together. All edges can now be smoothed by means of a heated trowel.

Flashings

It is recommended that the THERMOFLEX be turned up the parapets 150mm. A DARAFLEX flashing strip of 300mm should overlap the turn-up in such a manner that 100mm of its width be on the horizontal plane and 200mm on the vertical. (See DARAFLEX data sheet)

Finish

No U.V. protection is required

Under Tile

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Thermoflexsystem

THERMOFLEX APPLICATION SHEET NO. 4
WATERPROOFING OF WATER RETAINING STRUCTURES

Discussion

THERMOFLEX is an ideal product for the lining of concrete dams.

Surface Preparation

All forms of contamination must be removed ensuring a surface free of any barrier to adhesion. Cracks or voids in the surface must be filled using HYPERCRETE, (modified cementitious material) and allowed to cure for a minimum of 24 hours. Should any form of expansion joint be present consult our technical department as to the correct method applicable. In no case should THERMOFLEX be laid directly over the joint.

Application

By means of brush or roller apply a thin uniform coating of THERMOFLEX PRIMER to the entire surface to be waterproofed at a rate of 6sqm/L. Observe fire precautions. Allow three hour drying period and “lay up” the area with the THERMOFLEX. Ensure a minimum of 75mm for overlaps. Fold THERMOFLEX back from the vertical surfaces and torch off the plastic backing sheet. Place heated THERMOFLEX onto the surface ensuring complete contact. Using a trowel lift up the membrane at the overlaps and torch, running along all the joints. Press the heated surfaces together. All edges can now be smoothed by means of a heated trowel.

Water Retaining Structures

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Thermoflexsystem

THERMOFLEX APPLICATION SHEET NO.5
WATERPROOFING OF VEHICULAR TRAFFICABLE AREAS

Discussion

The system was developed to meet the need for an economically priced, high performance, low maintenance system. With increased congestion and greater demands for city parking, parking decks have become increasingly common and require a completely trafficable waterproofing system.

Surface Preparation

All forms of surface contamination must be removed to ensure a smooth surface, free of any loose material, or any other barrier to adhesion. Cracks or voids in the surface must be filled using HYPERCRETE (modified cementitious material) and allowed to cure for a minimum of 24 hours. Should the parapets be rough a HYPERCRETE slurry should be applied over the area which is to receive the flashing. Fullbore covers should be removed to facilitate dressing in” the waterproofing. It is recom­mended that the full-bores be checked to ensure that they function correctly.
Finally an assessment should be made as to what extent, if any, ponding is likely to occur. Standing water present after rain and run-off in excess of 5mm in depth is considered as excessive. A topping of HYPERCRETE in such areas is recommended. Expansion joints (if present) should be sealed and a PVC slip sheet placed. In no circumstances should the waterproofing be laid directly over the expansion joint.

Application

By means of brush or roller apply a thin uniform coating of THERMOFLEX PRIMER to the entire surface to be waterproofed at a rate of 6sqm/L. Observe fire precautions. Allow 3 hour drying period and “lay up” the area with THERMOFLEX 3000. Ensure a minimum of 75mm for overlaps. Using a trowel lift up the membrane at the overlaps and torch, running along all the joints. Press the heated surfaces together. All edges can now be smoothed by means of a heated trowel. Now lay up the area with THERMOFLEX 4000 and repeat the procedure with regards to the overlaps.

Flashings

It is recommended that the THERMOFLEX be turned up the parapets 150 mm. A DARAFLEX flashing strip of 300 mm  should overlap the turn-up in such a manner that 100 mm of its width be on the horizontal plane and 200 mm on the vertical. (See DARAFLEX data sheet)

Topping options

1. THEMOFLEX 2mm slip sheet is loose laid directly onto the THERMOFLEX system. The system can now receive the topping of warm/cold premix.
2. THERMOFLEX 2mm slip sheet is loose laid directly onto the THERMOFLEX system. A layer of sand is applied into which pavers are embedded.

Notes:

Initially the surface will appear too soft and a certain degree of surface loss will occur due to abrasion. This is normal and will stop as continued compaction is experienced due to traffic. Shrinkage cracking will also occur and is normal, not affecting the under­lying waterproofing membrane.

Expansion Joints

Owing to the variations experienced in service requirements contact our technical department for the correct detail before commencement.

Maintenance

It is recommended that an inspection of the wearing surface be conducted after 5 years. High traffic areas adjacent to onramps may require a maintenance topping although normally this is not the case.

Vehicular Trafficable areas

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Thermoflexsystem

THERMOFLEX torch-on reference list

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