Patio deck waterproofing

Patio deck waterproofing 
Plans
Section C-C
Section D-D

Deck construction

Deck preparation and construction

As part of a huge basement complex, the bungalow section has a patio deck above the gym below. Midland Tanking arrived on site with the ground floor slab in place. This floor was created with pre-cast planks, laid on top of the retaining walls below.

Pre-cast plans are laid with small gaps between the to allow for thermal movement, which is necessary but not ideal for waterproofing. Two layers of a 1200 gauge membrane was placed on top of the planks, creating a slip coat. This allows the planks to expand and contract per their design without stressing the layers above.

Reinforcing was laid across the planks and DPM, finally the deck was shuttered and cast with waterproof concrete. The concrete deck has a fall away from the building of 1:60 to ensure no water ever pools. This concrete created a stable and cohesive surface on which to apply the waterproofing.

Reinforcing for patio deck waterproofing Concrete for sub patio deck waterproofing Substrate for waterproofing castPatio deck waterproofing concreteNew deck created for patio deck waterproofing Edges chamfered for patio deck waterproofing 
Patio deck waterproofingCementitious waterproofing slurryLayer two of patio deck waterproofingCementitious waterproofing across deckCementitious waterproofing across deckCementitious waterproofing across deckAll surfaces preppedPriming layer for patio deck waterproofingPatio deck waterproofing primedPatio deck waterproofing priming layer

Waterproofing Details

Midland Tanking undertook this projects patio deck waterproofing with their in house designed four-stage waterproofing technique. As part of a new build basement complex however, two forms of waterproofing were required to meet Local Authority Building Control and 3rd Party Warranty Providers.

Primary waterproofing system

Four stage patio deck waterproofing – Barrier protection

Once the deck is cast below the surface is fully and thoroughly cleaned and a type A, cementitious slurry is applied across all surfaces. Once cured all surfaces are primed to give maximum adhesion for the primary waterproofing layer.

Two layers of a liquid applied waterproofing membrane are applied across all surfaces with a fiberglass layer embedded in the first. This acts as the primary barrier for the waterproofing layer.

The final step of the four stage process is to protect the membrane. A 1200 gauge DPM is laid as a slip coat followed by a drainage membrane. This membrane is installed to take any water away from the deck, preventing any pooling.

Secondary waterproofing system

Structural Slab – Integral protection

The structural slab above the pre-cast planks was cast in reinforced concrete with an waterproofing additive.  This slab was tied into the basement retaining walls below, creating a complete waterproofing concrete box.

Both waterproofing systems were designed by Certified Surveyors in Structural Waterproofing (CSSW) in accordance with BS8102:2009

All waterproofing materials were supplied by Triton Systems Ltd

Patio deck waterproofing project details

Categories:
Client: J Mason Associates
Location: Walsall
Surface Area: 35 square metres
Completed: 2024
Architect: J Mason Associates
Link: Visit project
Primary waterproofing layerAll edges and surfaces with waterproofing membranePatio deck waterproofingFiberglass mesh embedded into waterproofing layersAll joints incorporated into waterproofingPatio deck waterproofingPatio deck waterproofing completedPrimary patio deck waterproofing layerSlip coatDrainage membrane applied on topDrainage membrane and slip coat to protect primary waterproofingPatio deck waterproofing