Timber framed properties and EWI

Timber-framed properties are constructed of heavy-weight timbers which are used to form the building shape and are then fitted together to create joints. This building method is mostly prominent in cold climates, and has been around for thousands of years. An added bonus of timber construction is that as long as trees are planted in place of the used ones, timber construction can be very green and environmentally friendly. So, pair this with an EWI system and you can count yourself as doing your bit towards the environment!

Timber framed structures are built to be tightly sealed against water and moisture, and are built as part of a dry construction process where, once weather-tight, the timber needs to dry out before the walls are further constructed.

Timber framed houses, however, do heat up and cool down much faster and aren’t as naturally energy efficient, so insulation is very necessary. These days, timber framed houses are constructed with wall boards backed with aluminium foil, but this is difficult to do if you live in an already-built, older property.

Insulation is also vital to timber framed properties since damp and mould can be detrimental to the structural integrity of the building. As any professional would tell you, timber framed houses cannot have cavity wall insulation because timber needs air circulation, otherwise it will rot and cause damp.

Installing a timber framed house with cavity wall insulation may invalidate your insurance, so if you live in a timber framed property, then external wall insulation is a great option for your home because the materials can allow for vital air circulation and breathability. Keep reading to find out about the most suitable materials for the job…

EWI and render for a timber framed property

When externally insulating a timber framed property, the EWI system that you want to choose ideally consists of the most breathable materials. For example, the Mineral Wool with our Silicone Render system.

Mineral wool (otherwise known as Rockwool) is a great option for timber framed properties because it is made of spun volcanic rock. It is therefore highly resistant to moisture (which is what you want with timber frames) and is the most fireproof insulation material out there. Timber is relatively slow burning but will not hold up as well as brick and masonry, so with the Rockwool insulation acting as extra fireproof support in the event of a fire, it could help to protect the property from too much damage occurring.  

We also recommend that during installation you use the DuPont™ Tyvek® FireCurb® Housewrap which will add an extra layer of fire protection and vapour permeability!

Your choice of render on timber framed properties is especially important as well. You maybe wouldn’t want to go for acrylic render, for example, because this is the least breathable. Technology has greatly improved the breathability of renders. Silicone render is a high tech, thin-coat render with vapour permeability and breathability. Silicone render is also perfect for timber framed properties as it will resist organic growth such as algae and mould – further protecting your timber frames!

We recommend that with timber framed properties, you use our EWI-225 Premium Adhesive because again it is breathable, high strength, water resistant and has high elasticity.  

Wood Fibre is Ideal for Old Timber Frames…

If you’re looking for an extremely eco-friendly way of insulating your timber framed property, you may want to consider our Wood Fibre insulation systems. We source our Wood Fibre insulation from Pavatex, who are committed to a completely environmentally friendly manufacture and timber sourcing process; so much so that they have achieved the prestigious NaturePlus certification.

Older buildings in particular need careful attention. Choosing materials that suit the requirements of the building structure is highly necessary, and indeed it seems obvious that with a building structure built of timber, you would want to insulate using Wood Fibre which is formed from waste timber shavings. Not only is it environmentally friendly, Wood Fibre insulation is extremely breathable, offering excellent thermal performance. Because of it’s breathability, Wood Fibre insulation is popularly used on older buildings with a lime render as a finishing coat; this is because older buildings in particular need to breathe, and the Wood Fibre really allows for this, lending its thermal capabilities without damaging the delicate building fabric.

We recommend using our Lightweight Basecoat in conjunction with our Wood Fibre insulation systems. The Lightweight Basecoat contains lime, which offers a high level of breathability and flexibility.

Read all about our Wood Fibre insulation here.

How is external wall insulation installed onto a timber framed property?

So how is this all applied to the timber frame? Well, ideally with a Mineral Wool EWI system: the DuPont™ Tyvek® FireCurb® Housewrap will be stapled onto the OSB board, then Mineral Wool will be laid over the top using the Premium Adhesive and metal mechanical fixings to secure it. After this, the Premium Adhesive is used as a basecoat on top of the Mineral Wool, and then finally primed and finished with a Silicone render. 

In terms of Wood Fibre systems, we recommend a dry-fix system. The Firecurb Housewrap is stapled to the substrate, then the Wood Fibre is secured to the substrate using metal mechanical fixings, after which the Lightweight Basecoat is applied and is finished using a Silicone Render or Silicone Paint.

Looking to compare all of the insulation options for your property? Our complete guide to our range of insulation materials is one click away.

Will EWI on a timber framed property take away from its appearance?

Many people think that if they install EWI onto their property then it will take away from the unique characteristics of the property. In fact, this just simply isn’t the case, because unique elements of your property can be recreated using materials which mimic the previous look of the property.

For example, on timber framed properties you may have exposed beams. This can be recreated using our wood panels which are made using a wood effect render, created with a silicone mold and then painted the equivalent colour. Brick patterns can also be recreated using our brick slips which come in a variety of different shades. You can also recreate pebbledash using the EWI-235 Dash Receiver (although not many people are that keen on it – check out our blog on how to replace pebbledash with coloured render!).

If you are a timber framed home owner and EWI is of interest to you, then do get in touch with us here at EWI Store. We can put you in touch with an installer local to you and we can give you an estimated quote for materials. We are also always happy to give technical advice!

Applying render to a range of substrates…

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