Wrimco Waterproofing Co -

A: Yes, and there is no need for a slip sheet since our SBS membrane 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: I am a builder and assuming I have engaged a reputable waterproofer to apply the most suitable materials for the various areas, how best can I ensure that my building will be watertight?

A: Probably the most important thing you should do is to provide a sound substrate that is reasonably smooth. It is always best for membranes to be applied to the structural elements of the building rather than applied finishes such as screeded or rendered walls, and to terminate under flashings. Any pock marks or hollows should be cleaned out, primed with Screedbond and cemented with 3:1 mix. Blockwork should be pointed up flush and if liquid membranes are to be used, bagging is recommended. Laitance and cement dust should be removed with a high pressure water jet, acid etching (followed by soda ash) or sand blasting. Naturally, once the preparation is completed but you have to wait for it to dry, make sure other trades are kept off the area as much as possible and especially important to keep it dry. Otherwise protect the surface appropriately, and do the same if there is a delay tiling or whatever after the membrane has been applied and of course, water tested.

Q3: What is your recommendation for waterproofing the wall and slab in a lift well where the excavation is in rock and the top of the wall is existing concrete?

A: My recommendation is to torch apply Wrimco SBS 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 Maxseal Flex acrylic/cement should be applied as 2 coats to the vertical surface of the cut slab and down 25 with 50mm Sontara polyester bandage over joints. Water test to ensure joint between the two materials has proved effective before rendering.

Q4: I am building a house with a basement and I need to build retaining walls.

A: The best product for you would be Durotech Duromastic BLW latex bitumen in 20li pails. Working on 1.5li/sqm.

Q5: I am looking to purchase approximately 6m2 of drainage cell and filter fleece for a planter on a concrete deck. Can it be purchased from you direct?

A: We can supply you direct. The 500 x 500 sections are snapped together to form 1m x 1m squares which can be taped to a pallet together with 10m2 of 1mm filter fabric. Since the injection moulded PolyPropylene (PP) drainage cell is quite sharp and hence could pierce the membrane, you should use a protection board such as our PACTIV PB4 made from extruded Polystyrene (XPS).

Q6: I have some wooden shelving that needs to go into a scientific laboratory. These shelves must conform to certain guidelines including..."be smooth, impermeable to water, cleanable, and resistant to damage by the cleaning agents and/or disinfectants that will be used in the facility." The shelves are currently raw woods. The disinfectant used in our lab would be considered quite mild and the shelves would only be wiped over with disinfectant occasionally. The shelves are to go inside a 15 degree C cabinet and have plastic containers placed on them. I have 10 shelves, approximately 520 x 440 x 15 mm in size. Can you suggest any products that might provide this type of protection to the shelving?

A: I would suggest Duroepoxy WBE which you can see from the technical data on our website is an easily applied, water based 2 part epoxy. Epoxies are well known for their chemical resistance.

Q7: I am a building designer in Melbourne. I am trying to source a product that can be applied to an exposed steel structure that will provide a thermal break between the steel and adjacent aluminium window frame. The intent is to use thermally broken aluminium double glazed windows, but I want to ensure the effectiveness of the windows is not lost with heat transfer through the aluminium frame touching the steel window surround. Do you have a suitable product?

A: Our PACTIV GreenGuard PB4 should be ideal and any styrene compatible glue could be used to stick it to the aluminium frame. Each 8kg bundle has 18.6 sqm approx 6.4mm x 600 x 1200

Q8: Please advise the best approach and a budget price for repairing waterproof membranes in 6 planter boxes on a building rooftop in South Brisbane. The planter boxes were installed by another contractor. The boxes have leaked on previous occasions. Do you have a Brisbane agent?

A: Assuming the water is not coming through the walls and thus bypassing the membrane, the best solution is to empty the planter and re-membrane it with Sopralene Flam 180 and then PB4 protection board, 30mm PP drainage cell on the base with 1mm filter fabric, 50mm double washed coarse river sand and then the planter mix. We are happy to assist you in Brisbane.

Q9: Can I directly adhere tiles to the surface of Wrimco Mulitseal pure urethane?

A: Wrimco Multiseal pure urethane can certainly have tiles adhered to its surface. It would be advisable to prime with a water based epoxy.

Q10: We are building a concrete wall that will be built up to an existing slab. There will be a step in the wall to the slab. Unfortunately because of the sandstone boulders above the rock we cannot get in to cut a flashing so I don't know what is the best way to waterproof the junction. What is your advice?

A: If Delta drainage cell is used in one piece (2m x 20m) and there is a flashing at the top of the concrete wall to cover its top edge, then this should be effective but unfortunately the galvanised Dowels presents a problem. Assuming they are inserted through the DELTA, urethane sealant could be applied but there will be minimal adhesion to the PP. Since concrete is to be used and not porous blockwork, this should suffice. I would recommend Wrimco BLW latex bitumen together with PB4 protection board to concrete upturn before the big stones are installed.

Q11: We are looking at waterproofing a rendered structure. This render has been placed onto a timber frame that produces a lot of movement. This has resulted in cracking in the render. What do you recommend? Can we use a textile in with the paint? What type of spray equipment is recommended for spraying this type of paint?

A: My recommendation is to apply 2 coats of Wrimco Durabit EF followed by 2 coats of Wrimco Durocoat AC Solar (assuming you want white); otherwise grey or white (other colours such as sandstone available at a small premium). The SBR latex will have the elastic properties required to accommodate the movement while the acrylic will provide UV resistance. You could reinforce the membrane with preferably a non-woven polyester textile such as SONTARA that will not inhibit movement, as does fibreglass. Standard airless spray equipment would be suitable and, since water based, easily cleaned provided it is done promptly.

Q12: I need to seal the outside of a concrete block wall. It is currently backfilled with soil, and is leaching water throughinto the building. I will be excavating back and inserting proper drainage after sealing.

A: Best solution would be to check mortar is pointed 100%, prime with Duroprime ARW and then 2 coats Duroproof BLW.

Q13: 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. 25 years ago we torched a sample onto our doorstep facing north and with no shade protection and it is still in excellent shape. The 1mm ceramic chips are a perfect UV absorber and are still attached.

Q14: I am having a problem with my leaking portable roof. It consists of a sandwich board ceiling/roof but the steel has pulled away from the foam backing (de-laminated). I have tried waterproof paint/membranes but it is still leaking. Do you have any suitable applications in your range of products?

A: I suggest you use our "Multithane UV" provided the foam is not polystyrene which would be dissolved by the solvent. Otherwise use our "Duromastic AC" external acrylic. Best of all would be to use our "Sopralene Flam Granules" but you would need someone to torch apply the 4mm SBS sheet.

Q15: I have some face brick walls and tiled floors to seal. Do you have a breathable silicate or similar product with a long lifespan?

A: I would suggest our Duroseal AR or Azcoseal which consist of an acrylic resin dissolved in an aromatic hydrocarbon solvent. Although the liquid is clear, it will have the effect of bringing out the darker hues in the brickwork as if it has just rained.

Q16: I have had a retaining wall built from Besser blocks and cement rendered. Now I would like to paint it but there is moisture coming from the soil side that shows through the render. I have been told that you may have a product which I can use with paint to coat the wall that will adhere even if the moisture does not completely dry. Is this correct?

A: Yes, we do supply DRIZORO products which may be used here but it is preferable to first remove the render as retaining the moisture within the wall may cause the render to break off or go drummy. In either case, the Maxseal Flex would be the best material to use.

Q17: We have an external balcony that is leaking water to an internal office. We believe the grout/cracks are the problem as we have temporarily stopped the leaks by sealing the grout with silicone. Do you have a product that we could either coat the grout or the entire area that is approx 18 sqm metres?

A: Yes, we would recommend a 4 litre can of DUROSEAL AR.

We open 7:30am to 6:00pm Monday to Thursday, 7:30am to 5:00 pm Friday, 9:00 to 12:00pm Saturday. Our shop address is 10 Hill Street Leichhardt (cnr John Street).

Q18: What is the best product for bathrooms?

A: Duromastic P15 is the preferred product as it not only complies with AS3740-2004 but also surpasses the test requirements of AS4858-2004. It is a Class III modified acrylic urethane membrane.

Q19: I am about to begin construction of a basement that will require around 460m2 of waterproofing membrane to the external walls which will have a very clean FC Sheet finish. All joints will be sealed with a urethane sealant. W hich product would you recommend to use in this situation? Do we need to use a plastic Coredrain product or is a Geotextile product sufficient to protect the membrane?

A: Hopefully the FC will be thick enough to permit a 4mm gap between sheets in order to insert 6mm closed cell backer rod, ie 10mm, to form the perfect joint for our PU25 urethane sealant.

Recommended quantities would be:

Duroprime ARW 3 x 20li , Duroproof BLW 29 x 20li with the BLW roller applied in 2-3 coats. It would be best to protect the membrane with "no nails" PACTIV PB4 rather than geotextile. With the PB4 there is no need for a plastic Cordrain product. Since each bundle opens up to approx 1.2m x 15m strips and the material is closed cell Polystyrene foam, it is very quick and easy to apply with smears of styrene compatible glue or duct tape to secure in place prior to backfilling.

Q20: 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 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 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 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.

Q21: I have a leaking shower and I would like to seal the tiles and grouting. What do you suggest?

A: I suggest you seal the tiles and grouting with a 4li can of Wrimco Duroseal AR.

Q22: I have an exterior deck on which I have laid compressed fibro sheets. I am undecided as to whether to tile or use a sandstone appearing paving paint (to match the pool area); either way I must use a waterproof membrane on the fibro. The deck area is 10m x 2.4m. Your Azcoseal products look appropriate. Could you let me know the cost for the area and comment upon the suitability?

A: Yes, the Wrimco supplied Azcoseal clear acrylic sealer could be used to seal the sandstone appearing paving paint provided the Xylene solvent would not affect it, but this is most unlikely. It is best to torch apply our Wrimco SBS Plain on the fibro and then tile. Alternatively, if you laid the fibro with 4mm gaps, inserted 6mm closed cell polyethylene backing rod and sealed with PU25 urethane sealant, you could use a liquid applied membrane, preferably our pure urethane "Multithane" after first priming with "Multiseal". Then prime with our water based epoxy WBE and then apply your paving paint.

Q23: 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 granules. For appearance, you could then paint with an external acrylic such as our "Durocoat 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 such as Wrimco "Screedbond" mixed with cement and cross rolled.

Q24: I would like to purchase the best product to seal my basement wall, which leaks very mildly at the join between the floor slab and vertical block wall during heavy rain - the block wall has been painted. Due to cost I would like to install it my self - approximately 20 linear meters. What would you recommend?

A: My recommendation is to apply Maxseal Foundation which we can supply. If there are any signs of salt deposits, then it is best to use Maxseal Foundation - the 7kg pack should be ideal. However the paint would have to be removed as these products will only work on concrete or brick

Q25: What is the best roof membrane?

A: Torch applied sheet membranes are guaranteed in thickness and are generally more durable.