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• Product and system specification - contact a manufacturer for advice

Make sure to install waterproofing membranes as per the manufacturer’s guidance. Specify, where possible, one company’s product suite, getting their specification advice ahead of time. Check for a system warranty, rather than a product warranty. That way, if there are any issues with the performance of the waterproofing products, it can be clearly addressed by the manufacturer/installer. 

Damp proofing

The same as with any typical timber building, adequate damp-proofing will be needed at ground level to stop moisture from the ground getting into your building. We already know we have to lift the WikiHouse structure and any timber sole plates up and out the ground by at least 150mm. Damp proofing will need to be installed below the WikiHouse frame and integrated into your substructure design. 

The damp proof layer should lap up and over some of your breather membrane, ensuring there is a continuous waterproofing layer. 

Need help with this?

• Building design and specification - Architectural designer
• Product and system specification - contact a manufacturer for advice

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A breather membrane stops moisture from the outside getting into your wall build-up, whilst letting moisture already inside the wall to escape.

It should be installed on the external side of the WikiHouse walls, between the chassis and the exterior cladding.

We recommend where possible using a low-emissivity breather membrane, often with a reflective surface, to maximise thermal performance.

The outside of your WikiHouse chassis is a flush and continuous surface so application of the breather membrane is typical and straightforward.

Need help with this?

• Building design and specification - Architectural designer
• Product and system specification - contact a manufacturer for advice

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Single ply membranes can work well for both the flat roof and pitched roof designed as they can be simply laid over the chassis.

A cold liquid applied membrane may also work well for roof terrace waterproofing, but it can be more expensive and messy to install.

Waterproofing layers must be installed correctly as per the manufacturer’s instructions. It is also worth checking that the roof finish you want will work with the waterproofing product you’ve chosen. Some finishes manufacturers may recommend you use their own waterproof membrane as part of their cladding system; this is often the case with green roofs and materials like standing seam.

The roof waterproofing layer needs to adequately lap over the breather membrane to ensure there is a continuous waterproofing layer.

Skylark is compatible with pretty much any type of window or door. What's more, the precision and predictability of the chassis mean that the units can be ordered in advance instead of needing to be measured on-site, so your project doesn't need to be delayed for weeks while you wait for them to be made.

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What type of windows?

Seriously, we mean it. You can use almost any type: fixed, sash, casement… timber, alumnium, alu-clad, uPVC. We believe that inward-opening, double-glazed tilt & turn composite windows look great and last well. Inward opening are easier to clean, allow for the use of shutters or shades, and give a strong sense of connection to the outside when open. Your door sizes and opening direction will need to align with regulations.

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Double or triple glazed?

Modelling by Leeds Beckett University suggests that actually the extra cost of triple glazing (in money and carbon) won't really pay for itself over the lifetime of a WikiHouse. Good quality, durable double-glazed windows are probably where it's at.

Incidentally, it is an under-acknowledged rule that if you want to make a house feel robust and expensive, spend the money on the window seals and handles. The Germans seem to know this. Angela Merkel was once asked what, for her, defines Germany as a nation. She replied

“I think of airtight windows. No other country can build such nice and airtight windows.”

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Sizes

WikiHouse window and door blocks have standard opening sizes that should be accurate to within 2mm.

However, you may find that window and door manufacturers offer standard off-the-shelf sizes, and these may be considerably cheaper than having your windows custom-made. If this is the case, we recommend adapting the Skylark blocks to create smaller openings.

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Seals and finishes

The most important thing is to make sure any gap between the unit and the opening is fully insulated, and fully protected from wind-driven rain using suitable flashings, tape, expanding seals or silicone sealant, and expanding insulation. It is impossible to overestimate the ability of cold wind or driven rain to find its way through even the tiniest gap around the edge of a window.

Make sure to design in a cill to the base of your window/door, and have it slope away from the building.

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Skylights

All the same applies to skylights (or 'rooflights'). There are a number of  companies who will make skylights that can be directly fixed onto the face of a WikiHouse chassis, making them surprisingly easy to install.

Openable skylights can be an important part of your strategy to keep the building cool in summer, by allowing hot air to escape upwards.

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Get the frames delivered before you start

We recommend getting the windows and external doors ordered, delivered and waiting (safely) on site before you start assembling the chassis. Once the structure is up, the installers will want to get it wrapped and weathertight within hours, if possible.

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You can clad WikiHouse Skylark in anything you like. It is up to you to select your material palette, taking into consideration any planning or building regulation requirements. Non combustible materials may be required if your project is close to another building or boundary line.

The WikiHouse chassis offers a continuous 18mm layer to fix your cladding material or substrate into. The detail for this needs to be designed to suit your chosen cladding material.