Q1: Can I pour concrete topping on a SBS waterproof membrane?
A: Yes, and there is no need for a slip sheet since Wrimco SBS has elastic properties together with a polyfilm on its surface (except where burnt off at the laps). Use PP drainage cell 500 x 500 and 1mm filter fabric. Some builders, however, like to lay a slip sheet but either way is OK.
Q2: What is your recommendation for waterproofing the wall and slab in a lift where the excavation is in rock and the top of the wall is existing concrete?
A: My recommendation is to torch apply Wrimco SBS sheet membrane to the underside of the slab above and then down to the base and sides of the wall formed by shotcreting over the rock. After the builder inserts the reinforcing pins, seal around with Wrimco SBS prior to reinforcing and shotcreting to form the lift wall. Where the opening is cut out, Wrimco cementitious liquid membrane should be applied as 2 coats to the vertical surface of the cut slab and down 25 with polyester bandage or butyl rubber tape over joints. Water test to ensure joint between the two materials has proved effective before rendering.
Q3: What is the lifespan of waterproof sheet membranes used on rooves exposed to the sun? What is the price per roll?
A: The lifespan of our granule membrane is confidently expected to be in excess of 30 years.
How do I use SBS sheet membrane on top of compressed sand instead of plastic sheet to ensure it is watertight?
Lay the SBS 1x10m sheets on top of the substrate with 75 side laps and 100 end laps and torch the laps. Since the hot gases formed will blow the sand around, you first have to consolidate the surface by either laying a blinding slab or simply spreading cement and water spraying to form a hard crust.
Just as it is best for a roof membrane to be fully bonded to the roof slab to prevent water tracking, it is desirable for the concrete poured on top of the SBS to adhere strongly to the membrane. We carry SBS Sanded sheet membrane for this purpose which saves having to burn off the polyfilm and broadcasting dry sand onto the molten surface.
Q5: I have a roof terrace approx 50sqm on two levels joined by three stairs which is currently tiled with terracotta tiles. These are now leaking through grouting and cracks and whatever waterproofing was in place is now compromised. Ideally I would prefer not to have to remove the tiles but instead apply a durable heavy-duty coating on top of them. There is only one doorway to the roof so I can adjust the door height. There is a table and chair set, but very low traffic area. Coating also needs to be able to be coloured (terracotta or light sandstone). I may also consider a concrete stencil if required. Could you give me some advice as to the best product set?
A: I would recommend removing 75mm render from perimeter walls, priming with our SBS primer and torch applying Wrimco SBS granuls. For appearance, you could then paint with an external acrylic such as our "W-AC Sandstone". Since there is likely to be moisture in the slab, it would be preferable to first apply Wrimco SBS as being black it will absorb the heat and bring up the moisture in the form of blisters. These can be cut and opened up to vent the moisture before torching back down again. The cap sheet is applied when no more blisters are formed. Alternatively, if the single layer system is preferred, seal the substrate with a moisture barrier.
Q6: How should I waterproof a 200 series masonry block wall in a below ground external environment? As an initial application I have painted a type of black mastic onto the face of the wall, followed by the installation of a 200 micron waterproof membrane. Is this the current technology and are these the correct products to use?
Should I use polyurethane membrane for this application? What polyurethane sealant should I use to fill gaps between some existing reinforced concrete columns and the masonry block walls.
A: Since the wall is masonry blockwork, a sheet membrane is preferred to a liquid applied type as it spans any voids in the mortar and is best for any expansion joints which are no doubt present.
Black mastic may make the wall look waterproof but seldom does it make it watertight. If a liquid applied membrane must be used, then polyurethane membrane would be a good choice. The 200 micron waterproof membrane is of course a plastic (polyethylene) film but provides very limited protection, is readily torn and water can easily by-pass the barrier.
The best practice is to spot torch the dedicated 6.4mm XPS protection board to the Wrimco SBS elastomeric. This Canadian manufactured 3.0m sheet is ideal for filling the gaps between the existing reinforced columns and the masonry block walls but if liquids are used, make sure closed cell polyethylene backer rod is used with the urethane (polyurethane) sealant.
How long after a concrete slab has been poured can Wrimco SBS be applied ? Is it be between 21 to 28 days ?
A: Depends on the ambient temperature, the end use, the type of concrete and how it was cured. It can be cured between 21 to 28 days. If the Wrimco SBS Granules is to be used as a single layer exposed membrane roof, then add a week to make sure.
High strength concrete will cure faster.
Concrete with a poor surface such as rain affected may be a problem. Priming will help but best to grind off to a sound substrate if high pressure water jet will not shift it. No one wants to acid clean and then neutralise with Soda Ash. I understand that curing under water for 48 hours or the use of a good curing agent will reduce overall curing time.
I am a development engineer and assessing a stormwater management plan for a residential flat building. For various reasons, the designer has placed a rainwater storage tank (looks like blockwork) in the centre of the building, with one wall adjacent to a unit, so that the stored rainwater would be on the other side of the wall from a habitable room. I am just wondering if your product would be suitable for use in this situation, as it looks risky to me. Also at one point the width of the tank scales off the drawing as less than 1 metre, so access would also be difficult.
A: Provided they use our Wrimco SBS 3.0mm 180 black with double detailing at the perimeters, corners and projections is used and the outside walls are void or waterproofed, there will be no problem, even with porous blockwork. The top of the membrane should either be turned over at the top or mechanically fastened. Our Canadian manufactured SBS has been used on several water tanks like this with 100% success. 600mm is the minimum width for satisfactory application.
If covered, the builder should supply an exhaust fan to keep the CO2 that results from the propane gas torch applications to an acceptable level. No primers are necessary so no solvent vapours which would clearly be a hazard in an enclosed space. Since condensation will occur on the roof of the tank, it should be waterproofed with our Wrimco BLW latex bitumen liquid applied as two coats to the surface after first priming with Wrimco WBE Hibuild (water based epoxy). Would be happy to provide specific comments on the plan and section drawings.
Q9: How do we waterproof a mild steel RSJ to an existing 2 layer bituminous membrane having mineral chips with a 10mm gap between them?
A: Since torching onto metal is difficult because the metal expands a lot when it soaks up the heat, it would be best to lay a first layer of cold applied SBS self stick membrane, over laing the existing membrane by 75mm. But first remove the mineral chips with a hot trowel 150mm from the edge and apply a strip of the self adhesive membrane over the 10mm gap. Ginally torch a cap sheet of SBS granules extending a further 75mm onto the existing membrane.
Q10: We wish to use your Wrimco SBS membrane on a roof deck with pebbles for a good appearance but are worried about only having a 50mm clearance between the outer edge of the circular column to a blockwork wall as illustrated?
A: Sealing the base of the column with our 90mm SBS flashing tape will permit the torch on membrane to be sealed satisfactorily to the column but will be difficult in the area where the gap is so small. Where this occurs, you can use our liquid SBS Alsan Flashing which is fully compatible with SBS membrane. Since you plan to spread gravel for appearance, you could use Wrimco SBS granule self protected membrane, also you could use Wrimco SBS plain with protection board for much the same cost.
We would like to install pavers on adjustable supports above two layers of your torch on SBS membrane. Are there any load issues? Is your membrane compatible with rubber or plastic packers.
A: There are no load issues as the compressive strength is 35psi ( 1 pound per square inch = 14.22kg/cm2). Regarding the packers, rubber or polypropylene packers are compatible but not plasticised PVC. 3mm offcuts of our SBS membrane or 3mm corflute make excellent packers.
Q12: I am currently designing a landscape on a carpark roof and have been researching your product. At this stage we have pavers on mortar on PB4 board on SBS membrane on slab. Is a double slip-sheet required and where in the profile would it sit?
A: The reason for using slip-sheets is to remove any stress to the membrane from movement in the mortar above that is adhered to the membrane. Hence they are commonly and correctly employed to separate a mortar bed from the plastic type membranes such as APP (wax) modified bitumen, plasticised PVC, etc., which are normally (and should be) semi-loose laid. Since Wrimco SBS is elastomeric, there is no need to employ a slip-sheet and the membrane is of course applied fully bonded to the substrate. With PB4 XPS board protection/insulation board (thermal and impact sound), the membrane is separated by 6.4mm EPX anyway. The PB4 is normally spot torched to the Wrimco SBS to prevent it blowing away prior to the mortar and pavers being laid.
You could use a slip-sheet on top of the PB4 to separate the mortar from the PB4 XPS board but there is really no gain and I think it is better for the mortar to adhere to the PB4 (which it will) so it sounds less "drummy". The PB4 XPS board would be able to accept any likely movement. Don't forget to show light (1.6mm) mesh reinforcement in the mortar bed, regular expansion joints and "Ableflex" at the perimeters so the mortar/pavers act as a raft floating in a sea of air.
We are building a house with a sub-basement near the high water mark at the bottom of a hill. How do we waterproof the crushed rock that the engineer has specified before pouring the slab.
Provided the crushed rock is rolled flat with no sharp points and any residual dust blown off, lay the Wrimco SBS reinforced membrane over the entire area and then seal the 75mm side laps with our special lap torching tool. Use our SBS Mineral HD (heavy duty) with polyfilm selvedge and take care to degranulate the 100mm end laps by pushing in the mineral into the molten SBS surface with a hot trowel for a black-to-black seal.
How do we terminate your Wrimco SBS onto a footing for a retaining wall that will be at the water table level?
Angle grind a slot and turn in the SBS, securing with an angle screwed through the membrane and seal around the screw head with Sopramastic (the downward pressure will seal the angle to the SBS just like a top washer).
Push down closed cell backing rod (BR) into the remaining space in the slot and seal with Sopramastic.
Q15: We need to penetrate two
layers of your SBS in order to install some 'play features' direct into the
concrete slab. Can you please advise the best way to ensure the system remains
A: It is best to drill and epoxy grout supports after
torch applying the SBS membrane.
Drill a hole in a piece of plywood, place over
the mark, and holding the plywood down firmly with your foot, drill down and
then remove slowly. This is to ensure that the membrane is not lifted and
remains fully bonded to the substrate. After cementing in the pipe or rod, the
waterproofer burns off the surrounding Polyfilm and when cool, seals with an
SBS mastic such as Sopramastic or Polyroof. Do not use urethane as the solvent
in the sealant will result in poor adhesion unless first primed with water
Naturally the pipe or rod should be clean and
primed appropriately with Metal Etch Primer. An alternative procedure may be used with
screwed studs. A washer is squeezed down onto the SBS with a nut plus locks nut
and the pressure makes a watertight joint just like a tap washer.
In the case of screw fixing
a pressure seal such as our 20x10x20 aluminium Z section to a wall, the SBS is
trimmed so the top 20mm is flush in order to provide continuous pressure to the
SBS which should be softened with the torch before fixing with self tapping
do we stop a leak between SBS granules and the 10mm thick gal support plate
bolted through the membrane?
the granules against to the plate with 2 part water based epoxy and then the
gal with ME Metal Primer after first wiping clean with Xylene. When dry, run a
small bead of Sikaflex FC to hold in place 6mm closed cell backer rod as bond
breaker and caulk 10mm x 10mm with Sikaflex Joint Sealant.