FAQ uPVC windows / Replacement windows

If you’re thinking of purchasing new uPVC windows / replacement windows, it is always useful to know something about the various options available today. We have listed some FAQ’s on uPVC windows / replacement windows together with our unbiased answers.

Q. Please could advise me on which is best for security internal or external glazing beads on uPVC windows / replacement windows as I have been told two conflicting answers.
Company A has told me that internal glazing is more secure on uPVC windows / replacement windows as there is no beading on the outside to remove.
Company B has told me that external glazing is more secure on uPVC windows / replacement windows because the glass is pushed against the beading from the inside, which then locks the beading in place on the outside.

A. There are elements of truth in both arguments. It is difficult to argue against internal beading being the more secure of the two options and on most occasions would favour this option.

However, it also true to say that externally beaded Upvc windows / replacement windows are less prone to 'leaks' through the beads as there is effectively an uPVC up stand on the inside of the window, which any water would have to rise above before showing on the inside. In fact, leaks of this type are very rare and only happen in the most extreme conditions such as by the coastal property or on the top of a hill with little or no protection. In any case, no matter what method of glazing is used, the window company should guarantee against leaks. The thing to remember is that all uPVC profiles have drainage channels formed during the manufacturing process to cope with this.

We suggest you make your choice based on the competence of the company you choose and your belief that they will be around to honour their guarantees in the future. Most uPvc windows / replacement windows companies offer perfectly good products with optional extras such as Pilkington K Glass and better security locking.

Unfortunately, it's often the case that the more you examine a product the more opinions you will be given, and the more confused you will be. We may not have given you the answer you might have expected, but hopefully this is of some help.

Q. I am thinking of having Upvc windows / replacement windows Installed in an old terraced property, which currently has sash box windows. Having received three quotes, I have also received three views on whether the whole sash box should be removed or the new units simply fitted within the existing sash box, leaving the internal wood in place.

One replacement window company said. The whole box sash should be completely removed to ensure a good job, the second said there was no need as the wood was original and was in good condition, the third said it doesn't matter, but fitting within the sash box will be cheaper. Please could you tell me who’s right?

A. When replacing box sash windows both methods can be used, some companies believe leaving the original 'box' in place perfectly acceptable providing the timber is in good condition, others suggest the complete replacement, which will be more expensive as more work and material is used, and this is one of the reasons that both options are offered. Complete replacement is best then you have 100% replacement sash window but if cost is an issue and the existing timber is in good condition, then fitting the new sash within the existing box sash should be perfectly acceptable.

Q. Please could you advise me what is best to have fitted in my new replacement windows toughened glass or laminated glass? I have two lively boys who are always running about and playing football, I have received conflicting advice and I am now confused.

A. Both toughened and laminated glass are forms of 'safety' glass. People often assume that toughened glass is some form of extra strong glass, perhaps something like 'bullet proof glass'. However, in our opinion, 'shatter safely glass' would be a better description of toughened glass.

It is certainly quite difficult to break, but not impossible. When it does break, it will break into very small sections. These may, if you are unlucky, give you some scratches or minor cuts, but will not pose the danger created by large glass shards formed when ordinary float glass breaks. Toughened glass is preferred for use in domestic replacement windows as laminated glass, when hit with force will crack, but is unlikely to smash. This makes it dangerous to use in any situation where it is likely you may need to break the glass in order to escape in the event of a fire.

The strength of laminated glass is, of course, an advantage if security is a major consideration. Laminated glass is also thicker - usually 6.4 mm - and as such will offer better insulation. However, this also makes it heavier with a corresponding rise in 'wear and tear' when opening and closing windows and doors. It is also more expensive than toughened glass.

Q. What is the difference between uPVC and PVCu? One company claims better aging, particularly of colour with uPVC.

A. To answer the question, is easy there is no difference between uPVC and PVCu. Both terms refer to unplasticised (hard) PVC, which is used extensively in building products where rigidity is an important attribute.

8 People Standing on a Plastic Table

Plasticized (soft) PVC, on the other hand, is used where flexibility is important such as to protect electrical wiring. It is purely a question of jargon and any claims of better performance by uPVC are incorrect.

Q. Please could you tell me what are the advantages and disadvantages of uPVC and aluminium for replacement windows?

A. uPVC windows offer the following advantages:

a) Good frame insulation;
b) Low maintenance;
c) Many companies manufacture uPVC profiles, making it a cost effective material;
d) Now available in wood grain and coloured finishes.

If it has a disadvantage, it may be that it has relatively low structural integrity. This is overcome with steel or aluminium reinforcement. In addition, it can be susceptible, especially in South facing situations, to 'expansion' in sunlight. Again, using 'fully reinforced' frames can remedy this problem.

Aluminium offers the following advantages:

a) Virtually no maintenance over its long lifetime;
b) Slim, strong sections that will not warp or twist;
c) About one third the expansion of PVC-u.

Its main disadvantage is that it is a relatively poor insulator. However, thermal break alumium frames are available, which offer better insulation.

Q. Please could you tell me should uPVC replacement windows should be reinforced with steel or aluminium.

A. In our opinion, there is not much to choose between galvanised steel reinforcement or aluminium reinforcement. Both do the job and leading companies use both alternatives. Steel is stronger, but more likely to rust if the galvanisation is compromised and aluminium is not quite so strong, but will not rust.