Contrary to popular belief, buying double glazing doesn?t have to be the fearful process many people expect it to be. Keep a level head; don?t be rushed, above all find a reliable installer and it should all be a piece of cake! However, just to nudge the score in your favour, here is a list if things you might like to check before signing on the dotted line.
A good double glazing contract should include:
- The price as well as listed fees for additional work
- Any arranged extras
- The contractual timeframe for work to be started and completed
- A thorough description of the materials to be used and the work to be done
- Your contractual rights to cancel, plus whether any monies already paid will be forfeit
- A clear outline of agreed payment details, including particulars of the deposit
It?s also a good idea to check that the VAT is included and of course: Always read the small print!
Sealants are great at preventing the penetration of noise, dust, air and gas and are usually used to fill in small openings. Typically, sealants are used for concrete and drywall, but are just as effective with other materials such as uPVC.
Fundamentally, no single silicone type should be used for everything. The problem is, their descriptions are all very similar and give little away. So which one is best for the job you need doing? Read on to find out.
The most common failures in joints occur when:
- The wrong sealant has been used for the job
- During the manufacturing stage, the joint width/depth has been made too big or small.
- The double glazing window joint seals have excessive movement
- A sealant of poor quality has been used.
If you are planning to seal in a crack anywhere, ensure you consider all of the above. Before carrying out the job, make sure all the protective tape is removed, the surfaces are clean and that there is no residue. Foam packer rod should be used if the joints are wider than normal.
In the double glazing industry there are two common silicone types:
- Neutral cure /Acetoxy cure
- Modulus ? High/low
Modulus explained:
The modulus sealants are split into two sections ? high and low. A low modulus will stretch comfortably when put under a small force, providing elasticity and better movement. On the other hand, a high modulus sealant is very rigid.
If you?re trying to decide which modulus if right for you, take the desired movement into account. In the double glazing industry it is accepted that linear expansion and contraction of joints and plastics is high.
So, a low modulus would suit this task, as it provides the movement needed. There are sealants that can accommodate up to 50% of the normal joint width.
Cure explained
The two forms of cure available are acetoxy and neutral, but again their names give little away.
Essentially, the difference is how well that adapt to the material the sealant is used on.
- As they cure, acetoxy sealants release acetic acid. This smells similar to vinegar
- Whereas neutral sealants release alcohol as they cure. They have virtually no smell.
Acetoxy cure
Acetoxy cure is the sealant most widely used as it is quick to harden and the more rigid of the two. However, it is said to have poor adhesion qualities and doesn?t ?stick? well to, glass, aluminium and polycarbonate.
Another downside is that acetoxy cure attacks and degrades polycarbonate. This is because of the chemical released.
Neutral cure
This type of sealant is the polar opposite of acetoxy and sticks well to many materials. It makes neutral cure great for aluminium and uPVC double glazing, as well as glass, stone and polycarbonate.
Acetoxy takes around 30 minutes to skin over, leavening a shinier finish. Depending on the temperature, thickness and humidity conditions, it can take one to five days to fully cure.
Neutral sealant is more expensive than acetoxy.
So which sealant should I buy?
Low modulus neutral cure silicone seems to be the most adaptable on the market. Its flexibility gives it great movement and has excellent adhesion with most materials.
This makes it the best silicone out there for windows, whether it be used for uPVC, wooden double glazing or aluminium double glazing.
For the job, the worst sealant has to be the high modulus acetic cure. Short term it may do the business, but it won?t take long to become ?unstuck?.
Unfortunately, just to put the spanner in the works, there is a low modulus acetoxy cure, so be sure not to buy the wrong type.
Tip: Make sure to check the movement capabilities when comparing sealants and prices. It should be marked as a %. Be aware that cheaper silicone sealants are bulked up by other materials, such as chalk power, making it an inferior product.
Bulked up sealants have a higher shrinkage rate and can be prone to discolouration and poor adhesion.
Not every tube will have the movement capability displayed, but you can always seek out the manufacturer?s data sheet.
So you?ve taken the first step and expressed an interest in researching double glazed windows, but where can you get the best information?? What types of double glazing units are best suited to your needs, what are double glazing costs and how should you obtain a quote from suppliers and installers?
Follow the link to review our Tips for Buying Double Glazing
I know it?s easier said than done, but if you are considering installing new windows in your home, don?t be pressured by double glazing salesmen trying to offer you a great deal.
Take your time, do a little research, have a look at online showrooms and take a stroll around the local area; quite literally indulge in a spot of window shopping – see what style of window looks good in buildings of a similar age and style to yours. As a general rule of thumb, the more in keeping with the style of the property, the better your new windows will look.
When do get in front of that eager double glazing salesman, be very clear on what you want and exactly what they are offering. Remember that many ?cheap? deals are only that price because the windows have limited functionality. Be sure that your quote includes all the security features you require, plus ask how much an upgrade would be, it might be less than you thought.
Another point to consider is openings – will all the new windows open just as you require? For example, windows above a conservatory are notoriously difficult for the window cleaner to reach, so you might want to consider twist and turn technology for easy cleaning.
In short, it?s a big decision with lots to consider and a sizable price tag for a job well done; so stay calm, don?t be rushed, get a quote from several reputable providers and be sure to enjoy your window shopping experience!
Homes without double glazed windows could be losing up to 50% of heat loss through their windows alone and that?s with the windows closed! This adds up to a staggering ?135 per year for an average household, that?s around 720kg of CO2.
No one can argue with the obvious financial and environmental benefits of double glazing, the problem is that just like boilers and water tanks, new windows or doors don?t rate highly when thinking of things to spend our hard earned cash on. Usually it takes the middle of winter and something to break before most of us actually do something about it.
Naturally few people shop around for boilers or double glazing in the summer when the weather?s nice. The summer is the most likely time to find the best bargains; wait until the heating?s broken or your energy bills are the equivalent to throwing ?5 notes on the fire and you can be sure that every engineer and double glazing fitter in the country will be rushed off their feet.
