Damp can cause huge problems and big bills if the problem isn’t dealt with quickly and correctly. If you don’t catch it early on, it can even affect your health, as well as destroying and damaging your property.
How to spot damp
There are a few ways you can identify damp in a property, if any of the signs here strike you, you may want to take a thorough look and deal with it quickly.
- One of the first things you may notice is a musty, unpleasant smell. The mould created by the damp can leave a scent on the air which isn’t nice to deal with!
- Have you noticed your wallpaper, carpet, paint or other surfaces changing colour? Your wallpaper may even be peeling and lifting up from the surface.
- Mould spots are a dead give away of an issue, if you spot these you will need to fix the problem. Move furniture around if you haven’t checked behind large items for a while.
- You may see the plaster become discoloured and marked going up to about 1 meter off the ground leaving unsightly tide marks.
- If it’s usually cold or even feels damp, and the surfaces feel cold and damp it could be a sign of damp.
- Condensation causes damp, so if you see a lot of condensation you need to address this too.
- Growth of mould can also attack the external walls, so be sure to check them as well.
- Don’t forget about your floorboards or skirting boards either, there may be damage signs there from damp.
How to fix damp
If you’ve spotted any of these signs, and want to get straight to fixing the problem, you need to make sure your surfaces are protected and fighting off the damp. For thorough protection, we suggest the Sika 1 Waterproofing System. This system uses different products to ensure that you keep moisture at bay!
How to use the Sika 1 Waterproofing System
The system helps to waterproof internal below ground structures like basements, cellars, vaults, tunnels and so on. You can even use it for swimming pools and other water containing structures. The pre-bagged system contains kiln dried specially graded aggregates and cements. When mixed with Sika 1 Waterproofer Liquid Admixture, they provide a multi-coat system for structural waterproofing. It provides a fully-bonded waterproof barrier which helps to prevent moisture, in turn preventing damp on walls and floors, indoors and outdoors.
Sika 1 Pre-bagged Render system consisting of 3 coats as follows:
- 1st coat Sika 1 Spritz & Bonding Coat Mortar @ 6mm
- 2nd coat Sika 1 Render Mortar @ 6mm
- 3rd coat Sika 1 Finish Mortar @ 6mm
Total System Thickness – minimum 18mm, additional coats of Sika 1 Render Mortar can be applied if necessary.
Sika 1 Pre-bagged Screed system consisting of 3 coats as follows:
- 1st coat Sika 1 Spritz & Bonding Coat Mortar applied as a bonding slurry
- 2nd coat Sika 1 Spritz & Bonding Coat Mortar at 10mm
- 3rd coat Sika 1 Screed Mortar at 20mm
Total System Thickness – minimum 30mm
All the above are minimum thickness, maximum thickness depends on substrate, working conditions and requirements. Loading conditions may require the screed mortar thickness to be increased.
Consumption & Dosage
Sika 1 Waterproofer Liquid Admixture is diluted 1:10 by volume with clean water to form a gauging solution.
- 1st coat 25 kg bag Sika 1 Spritz & Bonding Coat Mortar (5.7L gauging solution)
- 2nd coat 25 kg bag Sika 1 Render Mortar (3.3L gauging solution)
- 3rd coat 25 kg bag Sika 1 Finish Mortar (3.3L gauging solution)
- A mixed 25kg bag of Sika 1 Pre-bagged Spritz & Bonding Coat Mortar will yield ~12.5L of mortar which is sufficient to cover ~2m² at 6mm thick.
- A mixed 25kg bag of Sika 1 Pre-bagged render or finish mortar will yield ~ 12.5L of mortar which is sufficient to cover ~2m² at 6mm thick
- 1st coat 25 kg bag Sika 1 Spritz & Bonding Coat Mortar (5.7L gauging solution)
- 2nd coat 25 kg bag Sika 1 Spritz & Bonding Coat Mortar (5.7L gauging solution)
- 3rd coat 25 kg bag Sika 1 Screed Mortar (2.5L gauging solution)
- A mixed 25kg bag of Sika 1 Pre-bagged Spritz & Bonding Coat Mortar will yield ~ 12.5L of mortar which is sufficient to cover ~1.2m² at 10mm thick.
- A mixed 25kg bag of Sika 1 Pre-bagged Screed Mortar will yield ~ 12.5L of mortar which is sufficient to cover 0.6m² at 20mm thick.
The substrate must be structural sound and generally brickwork, dense concrete block and concrete normally provide satisfactory substrates. All surfaces should be clean and free from surface contaminants and laitance to achieve an adequate bond.
- WALLS/BRICK: All existing treatments shall be completely removed and the exposed surfaces roughened by mechanical or water blasting techniques, followed by washing down and brushing to ensure full removal of all loose material. Mortar joints should be bonded and sound. Any defective mortar joint should be raked out to a depth of 12.0mm and repointed using Sika 1 Finish Mortar made up with clean water.
- WALLS/CONCRETE: All laitance shall be removed to expose coarse aggregate by mechanical or water blasting techniques. On new concrete walls Sika Rugasol MH Concrete Retarder can be applied to the face of the shuttering followed by wire brushing and washing of concrete surfaces.
- FLOORS/GENERAL: All existing treatments shall be completely removed and the exposed concrete floor mechanically prepared, washed down and brushed to ensure full removal of all loose debris to give an exposed aggregate finish, free of laitance, and surface contamination.
Place the correct amount of gauging solution into a mixer and add the mortar and mix until the gauging liquid has been evenly dispersed, approximate 3 minutes. The Sika 1 pre-bagged waterproofing system should be mechanically mixed using a forced action mixer or drill and paddle mixer to limit the amount of air entrapment and to ensure thorough dispersion of the Sika 1 Waterproofer Liquid Admixture. A tumble mixer is not suitable for mixing.
Ambient Temperature should be between +5°C and +30°C. Immediately prior to application the substrate must be soaked with clean water however no standing water or puddles should be present. Working time for all products is approximately 30 Minutes at 20°C.
Wall and Ceiling Render System
- First coat – Sika 1 Spritz & Bonding Coat Mortar applied as a 6mm spritz coat by casting on vigorously over the complete wall surface.
- Second coat – Sika 1 Render Mortar applied by trowel at 6mm as soon as the first coat has stiffened sufficiently (typically 4-5 hours later), with a coved trowel used at internal corners. A splatter coat of Sika 1 Render Mortar or Sika 1 Spritz & Bonding Coat Mortar, mixed with plain clean water or gauging liquid, is then applied to serve as a key for the third coat.
- Third coat – Sika 1 Finish Mortar applied by trowel at 6mm, finished with a wooden float to achieve a closed surface with neat arises.
Should additional coats be required Sika 1 Render Mortar is repeated on the second day and subsequent days before the application of the Sika 1 Finish Mortar final mix.
Floor Screed system
- First coat – Sika 1 Spritz & Bonding Coat Mortar is applied as a bonding coat in sections by vigorously working into the surface using a stiff brush or broom.
- Second coat – Sika 1 Spritz & Bonding Coat Mortar is applied by trowel by waiting for the mortar to become a plastic consistency. This coat is laid whilst the first coat is still wet at a minimum overall thickness of 10mm.
- Third coat – When second coat has hardened sufficiently to walk on, apply third coat. Sika 1 Screed Mortar is prepared to a semi-dry consistency and is applied in a coat of 20mm minimum thickness whilst the previous coat is still green. Tamp vigorously, until moisture rises to the surface and finish off with a wooden float to achieve a flat, closed surface or to achieve a surface finish to suit the final floor covering. If third coat exceeds second coat by more than 24 hours, apply another bonding coat of Sika 1 Spritz & Bonding Coat Mortar.
- Corner Fillet – Use Sika 1 Render Mortar to form any optional cornet fillets.
- FORMATION OF LAP JOINTS: When applying Sika 1 Pre-bagged Waterproofing Screed systems, successive coats will be lapped to eliminate a continuous butt joint through the mortar. The joints between successive coats of render and screed at day work joints must be stepped back to allow overlaps of a minimum 100mm in length. Before continuing with the new work the lap will be prepared by brushing and priming with a bonding coat of Sika 1 Spritz & Bonding Coat Mortar.
Notes on Application
- Detailing and specification support is available from our Technical Department.
- Levelling of walls and screeds Undulating surfaces should be levelled after application of the Sika 1 prebagged systems for optimum performance.
- Joints/cracks subject to movement should be treated using Sikadur Combiflex joint system prior to the application of the Sika 1 Pre-bagged waterproofing systems. Cracks leaking water should be sealed with Sika Injection systems or plugged using Sika 4a.
- Curing: Sika 1 Pre-bagged Waterproofing render systems must be kept moist during the work period and for a minimum 7 day period after final application to stop drying out and reduce cracking. They should be prevented from being exposed to sudden changes in air temperature and relative humidity.
- Fixings should be bonded onto the Sika 1 Pre-bagged waterproofing system or pockets created before installation. See standard detailing sheet.
- Timber battens can be adhered onto the Sika 1 Pre-bagged Waterproofing Render using Sikaflex 11 FC+ to facilitate the application of a dry lining system.
- Sikadur 31 CF can be used to structurally bond fixtures to the Sika 1 Pre-bagged waterproofing system.
- Ensure the Substrate is structurally sound before installing Sika 1 Pre-bagged waterproofing systems.
- Overcoating To provide a smooth finish suitable for decorating, use Sika Whitewall plaster or SikaMur finish plaster to the wood float finished third coat of the Sika 1 Pre-bagged Waterproofing render system.
- Sikagard and Sikafloor coatings can be applied directly to Sika 1 Pre-bagged Waterproofing Systems to enhance durability and aesthetics.
- Sealing of Pipes and Ducts – Refer to detailing sheet.
- Reference should always be made to the Detailing, Architectural and Engineering Consideration Sheets, Agrement Certificates and Installation Guides.
Notes on Limitations
- Puncturing the system can compromise its integrity.
- Do not exposed to frost while curing.
- Allow Sika 1 Pre-bagged Waterproofing render system to sufficiently dry out before over coating.
- The structure and its elements must be capable of withstanding the developed water pressure and other anticipated loadings without cracking or delaminating.
- Advice should be sought from independently qualified personnel with knowledge of the structure and local ground conditions.
- Never score or scratch any of the Sika 1 coats to provide a key.
- Do not use gypsum based plaster over Sika 1 system. Refer to plaster manufacturer for advice on suitability of product for use in waterproofing works.