Archive for September, 2013

Multi-level basement – January 2014 update!

Tuesday, September 24th, 2013
Platon P20 cavity drain membrane (to provide Type C waterproofing) has now been installed to the East Building at this major London development:

Platon P20 installed

A further update on this major project: The ground workers are now down to level -5 and are nearly ready for the next phase of waterproofing – using Type A and Type C waterproofing systems from Triton.

Ground workers have reached level -5

Down at level -5 and ready to install Type A & C waterproofing systems

We started to report on this major central London project earlier this year (see further down page). It’s a ‘top down’ construction which will eventually comprise five storeys below ground.  A further two buildings are planned alongside each with three storey basements. Triton will eventually be supplying 9,500 m2 of Platon P20 cavity drain membrane which are being applied throughout to walls and floor slabs.
To date TT Super and TT Vapour Membrane has been applied to all wall/floor junctions of all earth retaining elevations to the intermediate levels, to reduce the associated risk of water ingress at these critical junctions. The same approach will be used as the lower levels are excavated and constructed.

June 2013:

Triton is supplying concrete waterproofing systems to a major multi-level basement project in central London.

Multi-level basement construction in progress

The basement construction is secant piled walls with BS 8007 concrete reinforced liner walls and slabs.
Triton has so far supplied approximately 9,000 metres of TT Waterstop (a ready to use pre-formed waterstop which swells up to 400%) and TT Swellmastic (a hydro-reactive expansion sealant) to all construction joints within the BS 8007 structure.

TT Admix, an ‘active’ concrete waterproofing admix has been incorporated to waterproof certain twin walls and Triton Colflex, a ready to use Hypalon jointing strip, has been installed to movement joints. Colflex detailing TT057-1(1)

Following construction, Triton will be supplying approximately 9,500 m2 cavity drain membranes to the site.

Below ground waterproofing for new build farmhouse

Tuesday, September 24th, 2013

Concrete waterproofed with TT Admix being poured on to site

Landmarks (UK) Ltd, a Yorkshire based developer, has used Triton waterproofing systems in the construction of a traditional two storey farmhouse. The property sits on a natural gentle slope, so the basement is fully buried to the rear with a raised patio area to the front.

The property was built using ICF (insulated concrete formwork) where polystyrene forms are used to contain the wet concrete when casting in-situ concrete walls – and are left in place.

Setting spacers and reinforcements to ICF walls

The lower slab was made waterproof by the installation of a membrane beneath it and the inclusion of Triton’s TT Admix in the mix.  TT Admix contains active chemicals that react with fresh concrete to generate a non-soluble crystalline formation that seals the concrete itself against the penetration of water or liquid.

Triton’s TT Waterstop, a pre-formed water bar which swells up to 350% when in contact with water, was placed into all joints. The shuttering around the slab had made provision for the concrete groove in the face of slab and the TT Waterstop was fixed into the groove using Triton’s TT Swell Mastic expansion sealant. TT Swell Mastic swells up to 100% when in contact with water, and has long lasting adhesive and hydro-swelling properties. TT Waterstop was also placed in the centre of the wall on top of the slab so that the joint between the wall and the slab was protected.

Triton TT Admix was incorporated in the concrete mix used to form the basement walls. The walls were filled in one day, with over 60m³ of concrete being pumped and compacted.

All joints between the polystyrene panels were protected with a width of Triton Fleeceband reinforcing fabric to give extra tensile strength. The external toe of the concrete slab had Triton Fillet Seal, trowelled into a wedge shape to make sure any flowing water flowed away from the joint. This joint was also protected with Triton Fleeceband.

Externally the basement walls were treated with two coats of Triton TT Vapour Membrane, a ready blended, single component acrylic modified coating, that provided the primary waterproof and gas proof barrier. Platon Double Drain, a membrane which, in this application, provides a drainage and protection layer, as well as working as a traditional cavity drain membrane which allows air movement between its face and the formwork, was then draped down the walls to connect to the land drain. The geotextile layer of the Platon Double Drain membrane is extended over the land drain to ensure that fines are kept out of the system. The external walls were then back filled.

Jon Rowlands, a director at Landmarks UK Ltd explained that although his company is steeped with traditional skills, they are actively seeking and using modern methods of construction to build energy efficient housing with low maintenance, and low running costs. He said “We use Triton products because they are ideally suited to our Nudura  ICF system and they have a long and respected history in the trade.”

“For example, the TT Admix is self-healing which is essential for use with ICF because each web that ties the polystyrene panels together is a potential leakage point.  The panels are strong enough to withstand a poker when full of wet concrete, so we don’t have issues with voids, but if there is capillary action along the webs, then the self-healing properties of the TT Admix are able to deal with this scenario. The high density polystyrene is also an ideal base for the application of TT Vapour Membrane because the two products bond together naturally.”

He explained “ICF works at its best when dry, so that full use can be made of the insulating characteristics of the product. This is why we use Platon Double Drain and TT Vapour Membrane to keep water away from entering the fabric of the building.  Using TT Admix in the concrete is the safety back up system because if there is a problem this can be repaired from within the building relatively easily.”

www.landmarksukltd.co.uk