Month: February 2017

What to do with your Satellite Dish and other fixtures

28 02/17
satelite dish external wall insulation

What to do with your Satellite Dish and other fixtures

When you get EWI installed, there are going to be things on the wall that will need adapting. We have touched on some of these things in previous blogs – your plumbing for example, your boiler flue, and your window sills will probably all need adapting.

Satellite dishes are no exception, but so often we get customers concerned about what will happen to their TV signal that we thought a whole blog devoted to them would be a good idea! Losing your TV signal can be a very emotive subject for some, so let’s take a look at the implications for dishes on EWI jobs.

Will I lose my signal with EWI Work?

Unfortunately, you will probably have a loss of signal if the insulation is going on the wall with the dish attached. There are a couple of issues here. Firstly, adding scaffolding in front of the dish will obscure its line of sight with the satellite, meaning it cannot receive signal. Even if the scaffold does not obscure the dish, it will have to be removed in order to extend the dish out on top of the insulation.

How do you extend the dish?

After removing the dish, a piece of timber is added to the wall. The timber is then covered with a piece of XPS insulation to bring it level with the rest of the EPS. The XPS is more dense than the EPS, and acts as a insulator to prevent a thermal bridge from the timber to the outside. After the wall is rendered and complete, the dish is refixed with long screws that go through into the timber underneath, creating a strong fix.

Can you put the dish elsewhere, or on the scaffolding during the works?

Whilst the dish has to be removed, it is possible to put it on another wall or on the scaffold during the works to ensure continuity of signal. It will likely require an engineer to adjust the dish and fine tune the signal however. For many customers, this added cost is not worth it for the week or two that the dish will be in place before being refixed to the wall. Our quotes do not account for this work, and there would be an additional charge for this service.

How about cable TV, Internet and phone lines?

Any cable TV, or cabled internet and phones, should not be affected by the installation. The wires may need to be moved or altered during the works, but this does not usually involve a loss of signal. In the rare cases where a cable is not long enough to be extended, an engineer may have to be called in to carry out an alteration, which can mean a short period of disconnection.

Can you move my BT line?

BT lines are not the property of the occupier or the landlord – they belong to BT, so we are not allowed to touch them. If you have a BT cable which will require moving or altering, you will need to get a BT engineer to do this work before the insulation is installed. Sorry but these are rules laid down by the telecoms industry, not us. The good news is that cable boxes and sky dishes do not have the same restrictions.

So if you have any reservations about works around your satellite dish, just speak to us first – we can discuss the works and your options.

Why you Shouldn’t Mix external wall insulation Systems

24 02/17
mixing external wall insulation system

Why you Shouldn’t Mix external wall insulation Systems

Systemically means effectively

What is an EWI System and what does it consist of?

There are around 60 BBA certified external insulation systems in the UK. That is a lot of choice, but what exactly does the system consist of?

There are several key elements that form part of this system. The insulation material, the fixing material, whether that be adhesive, mechanical or both, the base coat, mesh, and top coat. There are lots of variations on this, along with peripheral items like beading, verges, over-sills and starter tracks. The core parts of the system are usually the sum of the approval from the accreditation body however.

We get asked fairly often whether we can mix parts from different systems to get a job done, or keep cost down, getting adhesive from one system and fixings from another. There are plenty of problems associated with this, so we want to highlight them in this blog and show why Be Constructive never mix insulation systems to complete a job.

Systems are Extensively Tested and Approved to Work as a Whole

Each system that is approved goes through rigorous testing, looking at production, installation and how various parts of the product perform together. If you combine two different systems, you don’t know whether it is going to perform as intended. Even worse is when part of a system is mixed with a product that is simply not right for external insulation work – this can lead to some really serious problems with the installation.

Warranties – Can you get them on a Mixed System?

Simply put, you shouldn’t be able to get an industry or insurance backed warranty with a mixed system – it has to be a fully approved system installed to the manufacturers specification to be able to qualify for these kinds of warranties. We realise that there are companies out there that offer standard company warranties on this sort of work, but can you really trust them when they are mixing and matching products like that?

Examples of Issues with Mixing Systems

There are numerous examples that we come across where systems are being mixed. Some of them are fairly benign and will not have a huge impact on the final performance, but others are really serious problems, and it sometimes isn’t as obvious as you would like to think, so we always recommend using an installer that uses a complete system.

For example, we often see phenolic boards being used in conjunction with an adhesive and render from an approved system. Most manufacturers do not approve phenolic boards for external insulation work, because they can lead to cracking of the top coat after just a few years. This is much more common than you might think, and we really stress the importance of only using EPS or Rockwool insulation.

Another problematic one that we see is where dry fixing is used on a system that is not designed for it. Some systems are designed not to use adhesive on the back of the EPS boards, with just the mechanical fixings holding the insulation on the wall. If the system is designed to be installed this way, then you will still be able to get a warranty, but if not, then the system will very likely fail over its lifespan and you will have issues with claiming for any work on insurance or getting a manufacturer involved.

Another problem we have come across is where a standard cement is used instead of a dash receiver for a pebble dashing job. This can lead to really poor adhesion of the dash and lots of bare patches.

There are numerous other examples of problems we see – from incorrect fixings causing spots to appear on the render, to poor adhesion of insulation to the substrate creating damp internally. What ever you do, make sure your installer uses a product that is BBA approved and that they install the product correctly, or you will be causing problems for yourselves down the line.






Loft Conversions and External Insulation

21 02/17
External Insulation

Loft Conversions and External Insulation

External insulation is often considered as part of wider refurbishment work in the home, and sometimes this can involve getting a loft conversion. In this bog we are going to look at the timing of the works and some of the things you should bear in mind when organising these works in combination.

Loft before EWI?

We recommend getting your loft converted first before carrying out the EWI work. This is for a couple of reasons. The first being that loft conversions are very extensive pieces of work that can, and probably will cause some sort of damage to the wall below, whether that be from something falling on it, splashed paint or from adjusting scaffold. Doing the EWI second makes sure this is not the case, and our teams wont need to go near the loft conversion, so no danger of any damage there!

Further, depending on how the conversion is done, there could be a need for the wall with the EWI on to be altered, and this will make it difficult for us to get the join of the EWI and the new roof just right. If the conversion is already done, we can bring the insulation up flush to meet it. It is important tht this process is planned however, as there are things the loft conversion company can do to make the connection better.

Scaffolding and EWI

If you are getting a loft conversion, you will have some very extensive scaffold over the property. It obviously makes sense to try and only use one lot of scaffold instead of using a second set for t
he external insulation. In order to ensure there is not too much adjustment necessary we advise the following for your scaffold contractor:

All scaffold should be at least 300mm away from the wall to allow 100mm insulation and render to be applied and pipework to be adjusted. Obviously if you are getting more or less insulation this figure can be adjusted accordingly. Further, for lofts you are not likely to have a lift in the scaffolding at 1st floor level, but obviously for EWI this will be essential. The key thing to remember is that every part of the wall that is being insulated needs to be accessible on the scaffold without having to stretch or overreach. It is obvious but not followed very often by scaffolders!

Last but not least, please ensure that there are no supporting pieces of scaffold up against the wall. If there has to be a support, then this should be kept to an absolute minimum as it makes the work much more difficult.

It goes without saying that any scaffold used needs to meet the relevant regulations and the contractor must have the relevant insurance and qualifications as required. This is something you can check with us if you wish to go ahead.

Do the loft conversion company need to prepare for the EWI?

Often with loft conversions there are no points at which the main walls of the building actually meet the converted loft. There may be a soffit all the way around that is untouched. In this case there is not issue with bringing the insulation to and sealing to the soffit as usual.

Some properties have a loft conversion with a tiled gable wall. In this case, a verge trim will be tucked under the tiles to create a good seal. Please speak to us first however, as this area can be prepared to make the join between the insulation and the tiles much more sound.

Can you Externally Insulate a Loft Conversion?

If you have an old loft conversion that you want to externally insulate, or you would like us to insulate your new loft conversion, we can do this using the same system as we do for tiled walls. This involves a phenolic insulation with timber slats and new tiling applied.





Should I Install Windows Before or After External Wall Insulation?

18 02/17
Windows Before or After External Wall Insulation

Windows Before or After External Wall Insulation?

Windows are often installed as an accompaniment to external insulation. It makes sense that if you are spending this kind of money on the external walls, the windows should be up to scratch as well. The obvious question then is whether this should happen before or after the insulation.

Windows after insulation, what can go wrong?

If your windows installer does a perfect job and measures the windows exactly right, then they can be fitted into the wall and then be sealed up against the insulation. Unfortunately, it is really common for windows to be slightly under or oversized and that means either cutting back some of the insulation or adding insulation to pack avoid. Either of these scenarios is not ideal and will lead to marking or scarring of the insulation or having to repair it. As you can imagine, this is going to add extra cost to the job.

Installing windows in the future

Obviously, over the 25 year lifetime of the insulation system, there will likely be a point where new windows need to be fitted. Windows don’t have as long a lifespan than insulation, so it is to be expected that new windows will be required at some point. What is the best approach here? The key thing is to ensure your installer is as careful as possible to not damage the rendering when taking the old windows out. We recommend removing them from the inside of the house to avoid knocking the render on the reveals. If any damage is done to the reveals, this is usually fairly easy and cheap to repair. Unfortunately, if any damage is done to the main elevation, this can prove difficult to patch without leaving a scar on the wall. And it may be necessary to re-render the whole elevation.

Insulation after Windows

The best way to do this is to install the windows first and then install the insulation right up to them with reveal beads. This ensures a snug fit and a great finish every time. The key thing to remember is to get the window sills pre-extended by your installer, as this will produce a much better finish than having to add over-sills and avoids extra silicon work.

Ventilation Awareness

The one thing that you should be aware of when installing both new windows and insulation at the same time is ventilation. In an old solid wall property with draughty windows, there are plenty of gaps for the moist air to escape and avoid condensation forming. Unfortunately, when the walls are both insulated and re-glazed, all these gaps can be blocked. To ensure that this does not create a damp issue, you should ensure that the windows have ventilation strips and that there are adequate vents on the wall. This needn’t mean draughts though. Modern ventilation boxes are much more sophisticated than old air bricks and thus would be able to diffuse the moisture away from the home without creating an excess draught.



Color render-Traditional Render

17 02/17
Color render

Traditional Render vs Colour Render


There are quite a few different types of rendering on the market, and it can be a bit confusing as to what is right for you. In this blog however, we want to clarify the main differences between sand cement traditional render, and modern thin color renders. These are the two main styles of render that are probably the most commonly used on the market today. You might also want to check out more about thick coat renders like Monocouche and Pebbledash, which are other commonly used systems.

Thin Coat Render and Mesh

One key difference between sand cement render and thin coats are that a layer of fibreglass mesh is sunk into the base coat of the thin coat. This ensures a rock solid stable surface on which to apply the top coat and resist any potential cracking. Sand Cement is a simple 1 or 2 coat application which has nothing to strengthen it. It is also very inflexible which makes cracking a real possibility.

Breathability of Render

Another key consideration is that silicon thin coat renders are breathable, whereas sand cement is much less so. For properties which require more breathable walls, this kind of render is by far the best option. Note that acrylic thin coat renders are not breathable.

Painting vs. Pre-mixed Colours

Another benefit of silicon or acrylic thin coats in particular is that you don’t need to paint them as part of the installation. The colour is mixed into the top coat directly, making the colour more hard wearing and preventing any peeling that you might get with paint over cement. It makes for a much better finish.

You should also note that thin coats do have a slight texture, even at their finest grain size, whereas sand cement will give a smoother looking finish. Some people are desperate for a smooth finish to their walls, but with a fine 1mm silicon render the texture is very fine and many customers feel this is a suitable substitute for a smooth finish.

Longevity of Systems

As with many materials, the quality of the installation is crucial in ensuring a long lasting render job. Unfortunately sand cement is really liable to cracking, even with a decent job of installing the render. You are unlikely to get a very long warranty on this kind of render as the installer can never be 100% confident in the material.

On the other hand, thin coat renders are very hard wearing and resistant to cracking, and as long as the job is installed well, can last for many years. You will probably get a 10 year warranty on this kind of render, and in some cases a 25 year industry backed warranty as well.

Cost of Thin Coat Render vs. Cement

Of course, sand cement is always going to be a cheaper product, both to install and to supply the material. Thin coat render has 3 main constituents – the top coat, the base coat and the mesh, whereas there is just one component of a sand cement render. This makes it quicker and easier to apply, but it does lack many of the benefits we have discussed.  Ultimately as a customer you have to decide whether you want a long term, quality product or whether you want to make do with a cheaper inferior one.

Extending Waste Pipes and Rainwater for external wall insulation

15 02/17
waste pipes

Extending Your Waste Pipes and Rainwater Goods for external wall insulation

When carrying out External wall insulation, it is obvious that any pipework and plumbing on the wall will probably have to be extended to accommodate the new insulation, which can be several inches thick. This is something we come across on every job and so we have to deal with many different scenarios on a daily basis.

How do you deal with Cast Iron?

Cast iron pipes are very difficult to adapt. As a matter of course we remove and replace cast iron with plastic equivalents wherever they need to be extended. Providing cast iron pipework is very expensive and the current pipes cannot be altered in most cases. If you do require cast iron pipes, timber supports will have to be fitted to ensure that the pipe has enough to hold onto the wall. So plastic is always the best option here unless you absolutely have to use cast iron – in a conservation area for example.

What Colour Pipes do you Supply?

If the pipes are already plastic we may decide to keep the current pipes and just adjust them, although we can of course replace them fully if you require us to, dependant on cost. It is not normally necessary to fully replace all pipes, but there are times when this might be the most practical option. In short, check with us if you have any specific requirements on the plumbing, otherwise you will get a straight forward extension of what is already there.

We will of course install the colour of pipes that you require, but this will need to be agreed prior to works being carried out. Otherwise we will install a standard colour our plumber has available. The usual colour of waste pipes is either black, grey or white. You can of course paint the pipes any colour you want to try and match a wall, but in our opinion this rarely looks very effective.

How do you extend Flues and Gas Lines?

All gas work requires a gas safe plumber to carry out the works. As such we have our own plumber that does this for us as part of the job. Flues are often tricky because if they are very old a new flue kit may not be readily available. In these cases we may have to leave a 30cm gap all the way around the flue – it doesn’t look as good as extending the flue, but it makes sure you meet the gas regulations without having to get a new boiler!

Of course, if your flue does not meet the current regulations we may need to make further alterations as part of the job, and check that ventilation is adequate.

Do you replace guttering?

Guttering is not replaced as standard. If the works require the guttering to be altered, then we may replace part or all of the gutter as required, but we won’t be obligated to do this – it really will depend on the requirements of the job. You can of course request us to replace the guttering, and this is often asked by the customer because having the scaffold up makes this very easy and inexpensive. It might also be a good opportunity to look at the soffits and facia.