Frequently Asked Questions for Cold Applied Liquid Waterproofing

1. Should I choose PU or PMMA?

LiquiTOP PU and LiquiTEC PMMA systems have many common features including, cold application methods, seamless waterproofing and adaptability to intricate roof details. Neither can claim an overall superiority over the other, however particular characteristics of each of these two polymers can be exploited by the specifier to enhance the specification of their waterproofing system.
LiquiTEC poly methyl-methacrylate (PMMA) liquids are two component materials and require a catalyst to be thoroughly mixed into the resin to form a seamless waterproofing membrane. This curing mechanism leads to the liquid rapidly curing which is an advantage where quick access to roofs and balconies is required. The system is reinforced with a polyester fleece and is applied wet on wet, meaning that the full system thickness is applied in one operation, which again makes it quicker to install to smaller areas. The two component nature of the liquid and the polyester fleece makes these systems more complicated for the installer to apply on site.
LiquiTOP polyurethane (PU) liquids are single pack materials and utilise a moisture triggered curing mechanism to form a seamless waterproofing membrane. This curing mechanism requires some atmospheric or substrate moisture to initiate the curing process, making it more moisture tolerant. The system is reinforced with a glass fibre mat and is applied wet on dry. Although this means that each coat needs to be allowed to cure before the next coat is applied, it also means that a larger area can be treated with the first/embedment coat, which allows a greater area to be temporarily waterproofed. The single component liquid and the conformable glass fibre mat make it easier for the installer to apply on site, especially over rounded of irregular details.

2. What substrates can Bauder cold applied liquid systems be installed on?

LiquiTOP PU and LiquiTEC PMMA systems can be applied to most substrates found in flat roofing applications including:

  • Reinforced bitumen membranes (RBM)
  • Single Ply
  • Asphalt
  • Liquid applied membranes (LAM)
  • Timber
  • Concrete
  • Brick/Block/Masonry
  • Metal
Some substrates will need to be primed as follows:
  • Mineral surfaced RBM – None
  • Exposed Bitumen – LiquiPRIME 1
  • PVC Single Ply* - None, but clean with PMMA Cleaner
  • FPO Single Ply* - Abrade and may need PMMA Cleaner or Special Primer 610
  • EPDM* – Special Primer 610
  • Asphalt* – LiquiPRIME 1
  • LAM* - None, but clean with PMMA Cleaner
  • Timber – LiquiPRIME 1
  • Concrete – LiquiPRIME 2
  • Porous Concrete – Cryl 287 Primer
  • Brickwork – LiquiPRIME 2
  • Metal – Clean with PMMA Cleaner
  • Mineral surfaced RBM – None
  • Exposed Bitumen – LiquiTOP General Purpose Primer
  • PVC Single Ply* - LiquiTOP PVC Primer
  • Asphalt* – None
  • Absorbent asphalt* – LiquiTOP General Purpose Primer
  • LAM* - LiquiTOP Reactivation Primer
  • Timber details – LiquiTOP General Purpose Primer
  • Concrete – LiquiTOP General Purpose Primer
  • Brickwork – LiquiTOP General Purpose Primer
  • Metal – LiquiTOP Epoxy Primer

*Always do an adhesion test

3. What substrate preparation is needed?

Substrates must be clean, dry and free of dust and any other contaminants.
Any algae or moss must be sterilized with a solution of diluted bleach. Proprietary biowash solutions are also available. Existing roofs must be swept clean and then power washed to remove dirt. Chippings must be scabbled off before power washing. Metals must be rust/oxidisation free and be free of paint or other coatings. Abrade surfaces to give a key. In all cases, make sure the substrate is dry.

4. What is the difference between LiquiDEK, LiquiDETAIL and LiquiBALKON?

These are fundamentally the same but with slightly differing properties. LiquiDEK is the roofing product and flows to give a flat surface. LiquiDETAIL is for details, it has better thixotropic properties which means it holds vertical upstand details better. LiquiBALKON is the reinforced balcony and walkway product. It is tougher and flows well to give a flatter surface than LiquiDEK.

5. Where can I use the LiquiTEC unreinforced balcony and walkway system?

The unreinforced balcony and walkway system can only be used on concrete or asphalt cantilevered or inset balconies i.e. they are stable and not over occupied spaces.

6. How do I repair asphalt cracks and blisters on a balcony before installing the LiquiTEC balcony and walkway system?

Cracks in asphalt must be raked out and cleaned before priming with LiquiPRIME 1 and then filling with LiquiPASTE or LiquiPASTE Mortar. Blisters must only be removed by cold work techniques, usually with a grinder. Once removed the exposed deck and surrounding asphalt will need to be primed and the hole filled flush with LiquiPASTE Mortar.
For filling larger horizontal or vertical voids 5-30mm deep, LiquiPASTE Mortar can be used. LiquiPASTE Mortar is made from catalysed LiquiPASTE mixed with Bauder Quartz 0.4-1.2mm in a ratio of 1:1.

7. What is LiquiPAVE RF Mortar and what can it be used for?

LiquiPAVE RF Mortar is made from LiquiPAVE RF mixed with Bauder Quartz 0.4-1.2mm as follows:
LiquiPAVE R (1 part)
Catalyst (4% average)
LiquiPAVE F (2.3 parts)
Bauder Quartz (2 parts)
The LiquiPAVE R needs to be catalysed before the LiquiPAVE F is mixed in and then the Bauder Quartz is added and mixed in. It is capable of filling horizontal voids and deflections of around 3-50mm e.g. low spots in a zero falls concrete deck.

8. Can Bauder Cold Applied Liquid systems be used for zero falls applications?

The LiquiDEK roof system can be used for inverted roof applications with zero falls and this is detailed in the BBA Certificate. Note that the definition of zero falls are falls less than 1:80 and that the finished roof surface must not have back falls. For exposed waterproofing applications, the roof should achieve a minimum 1:80 fall.
For exposed balcony systems, the surface must always be to falls as standing water will be a slip hazard, especially if it freezes.

LiquiTOP roof systems have been designed and have BBA certification for use in exposed roofing situations and should be use on roofs to falls to avoid unsightly ponding on the finished roof.

9. I want to use tiles as the wearing surface on a LiquiTEC balcony, how do I do that and what tile adhesive can I use?

Tiles can be used as the wearing surface for the LiquiTEC reinforced balcony and walkway system. To provide a key Bauder Quartz is bonded to the waterproofing layer either in LiquiPAVE RF or LiquiBALKON. The tiles are then bonded to the quartz surfacing. Any appropriate exterior tile adhesive can be used as long as it is not solvent based.

10. What colours are available in the LiquiTOP products?

The LiquiTOP PU products are all available in two shades of grey: Dark Grey (approximately RAL 7011) and Mist Grey (approximately RAL 7040). Both colours are interchangeable as embedment and top coats and are UV stable giving a waterproofing membrane that is UV stable throughout. For aesthetic reasons we usually suggest that Dark Grey is used as the top coat.

11. What colours are available in the LiquiTEC products?

The LiquiTEC range of products are all provided in various shades of grey.
LiquiDEK, LiquiDETAIL and LiquiFIBRE are all approximately RAL 7031 (Blue Grey).
LiquiBALKON is approximately RAL 7032 (Pebble Grey)
LiquiFINISH is available in RAL 7031 (Blue Grey), RAL 7030 (Stone Grey) or RAL 7043 (Traffic Grey)

12. What is LiquiFINISH used for?

The main use for LiquiFINISH is as a sealer coat to the exposed LiquiTEC balcony and walkway finishes or maintenance walkways on LiquiTEC roof and terraces where it is applied over the quartz.

It can also be used if the colour of a finished LiquiDEK roof needs to be changed for aesthetics. LiquiFINISH is available in RAL 7031 (Blue Grey), RAL 7030 (Stone Grey) or RAL 7043 (Traffic Grey). Other colours are available, but they often have long lead times.AL 7043 (Traffic Grey). Other colours are available, but they often have long lead times.