Month: September 2015


Insulating External Walls With Wool

28 09/15
Is Insulating External Walls With Wool Worth It?

Is Insulating External Walls With Wool Worth It?

Insu­lat­ing solid walls or any other type of wall that has poor insu­la­tion is absolutely the opti­mal thing to do – not only from an energy effi­ciency per­spec­tive but if under­taken exter­nally will also give your tired façade a renewed look.

There is a lot to be said about the mate­ri­als that are used for this insu­lat­ing process and many sys­tem design­ers out there will argue their point-of-view.  If you are insu­lat­ing the walls exter­nally you can use a num­ber of mate­ri­als includ­ing: expanded poly­styrene, min­eral or rock wool, cork and phe­no­lic resin. If the process is inter­nal you could use min­eral or rock wool, as well as sheep wool and phe­no­lic resin.

Although wool insu­la­tion for walls is not the most pop­u­lar prod­uct as yet, it cer­tainly has advan­tages over other mate­ri­als.

Mineral wool insulation is breathable

The min­eral wool sys­tem is what the indus­try refers to as “open vapour sys­tem”, which means that effec­tively mois­ture par­ti­cles can find a way from one side to the other through the mate­r­ial and the masonry walls. Do not con­fuse this with being prone to damp issues – an open vapour sys­tem will absorb mois­ture in the wool fibres and dis­si­pate this through the breath­able top coat of the ren­der that was installed.

If your brick ties are very tired and the brick itself is prone to mois­ture, then this could be the solu­tion for you. Effec­tively the dam­aged brick may never be fully dry when apply­ing the wool insu­la­tion sys­tem. If you then install the open vapour sys­tem like wool it will allow the mois­ture the abil­ity to dis­si­pate through the mate­r­ial and out to dry, mak­ing this insu­la­tion mate­r­ial really good for these types of sce­nar­ios.

A closed vapour sys­tem on the other hand stops like EPS the mois­ture escap­ing on the out­side which is why in some cases when installed on prop­er­ties it shows signs of damp on the inside.

Fibre glass mesh on rendering systems

15 09/15
glass mesh on rendering systems

Why is fibre glass mesh so important on rendering systems

If you have had the solid wall insu­la­tion installed or a new ren­der­ing sys­tem put onto your wall, then you may have seen the fit­ters empha­sise how impor­tant it is for them to install the fibre glass mesh.  When the piece is being installed it is skil­fully sunk into a thick layer of adhe­sive mor­tar. A notched trowel leav­es a nice smooth sur­face for the top coat to be applied.

For insu­la­tion sys­tems, it is an essen­tial piece of kit that is installed on top of the insu­la­tion and just under the final ren­der. It binds the whole thing together and gives the new insu­lated wall much needed flex­i­bil­ity.

In the rest of the blog we spend a bit of time going over some of the ben­e­fits of this piece of kit. Hope­fully if you are a builder or an archi­tect, you will take this away, and poten­tially look to inte­grate some of these ideas onto your future projects.

Gives the finish strength and flexibility

An obvi­ous ben­e­fit of the fibre glass mesh on rendering systems is its abil­ity to bind the insu­la­tion layer or the exist­ing wall into a nice and strong fin­ish. When the mesh is sunk into the adhe­sive basecoat, it pro­vides a solid hard­ened layer. Should any­thing hap­pen to the top coat, the fibre glass mesh inter­wo­ven into the adhe­sive will hope­fully not fail. This allows you to repair any parts of the damaged surface render.

If you ever feel a piece of EWI fibre­glass mesh in your hands, then try to pull it, you will notice how flex­i­ble the sys­tem is. Now imag­ine if some­thing hap­pened to the prop­erty itself. For exam­ple, you have some move­ment around the win­dow lin­tels, or the prop­erty moves. The mesh is designed to absorb most of that impact. By stretch­ing out, it will allow you to keep the sur­face look­ing visu­ally intact.

Accord­ing to the EWI Pro (sys­tem designer) instal­la­tion guide, fibre glass mesh sheets should be installed with an over­lap rather than butting up against one another. Refer to their train­ing guide for more details.