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How to waterproof cellar walls with Basement Mesh

Basement conversion has continued to grow in popularity as more and more people seek to create extra living space out of what they already own, as opposed to moving home.

Any such conversion must be carried out by trained profes­si­onals utilising materials and tools of the highest quality in order to ensure a safe, dry space is created. Basement water­pro­ofing is an essential phase in the delicate conversion process and Baseline Mesh is designed to facilitate the effective work of the profes­sional.

What is Baseline Mesh?

Baseline Mesh is a cavity drain membrane which allows wet walls both above and below ground to be isolated.

What is it made from?

Poly­et­hylene, a material of extremely high density, toughness and durability. To the front face, mesh lathing formed from strong HDPE is welded which will subsequently allow plaster finishes, adhesive dabs and plasterboard to be directly applied. There is also a complete range of ancillaries available from pumped drainage systems to mechanical ventilation units.

How does it work?

Blazoned with large 8mm studs, Baseline Mesh delivers superlative drainage capacity while simul­ta­ne­ously providing a source of ventilation. It’s stable at both ends of the temperature scale and can be finished with proprietary lightweight plasters or, if a more traditional approach is preferred, with 2-coat 1:1:6 cement:lime: sand render and a skim to finish the job.

Where can it be used?

Extremely versatile, Baseline Mesh can provide dry and habitable living space almost anywhere that suffers chronic damp conditions but it most often used in basement conversions. Dry lining with bonding plaster works well when the plaster is applied in >8mm thick dabs covering at least half of the membrane surface; once everything is dry then papering or painting can commence.

How is it installed?

  1. PREPARE all surfaces

  2. REPLACE any friable or salt-conta­minated plaster

  3. ISOLATE sources of moisture

  4. TREAT any appearances of mould/fungi with a suitable biocide

  5. SPACE fixings at 300mm centres both vertically and horiz­on­tally, working from the centre of the membrane to its outer edge.

  6. DRILL 8mm diameter bored through the membrane to 70mm depth

  7. FEED 70mm plaster plug through seal and drive into the bores with repeated light tapping motions; this fastens the membrane securely to the wall and creates the essential waterproof seal at each separate anchor point

  8. INTERLOCK edge-studs, seal seams between sheets using waterproof butyl tape; wall and floor junctions are sealed with butyl corner detail

Any more details?

  • In a basement without passive drainage, Baseline Mesh must be used in conjunction with an appropriate sump/pump facility

  • Suitable for water­­pro­­ofi­­ng in accordance with BS8102:1990 to provide Type ‘C’ drained protection to below-ground, structures

  • Delivers a Grade 3 or 4 dry environment that is suitable for domestic or commercial use.

  • Each roll is a standard size of 2m x 20m for a total surface area of 40 square metres

  • The sheet thickness is just 600 microns and has a density of 0.7kg/m2

  • A load bearing capacity of at least 50 kN/m2 is guaranteed

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