MAGNETIC SECONDARY GLAZING

[sarah j]

Hello , wonder if anyone can tell me how good Magnetic secondary glazing is ? Ive seen on a previous thread someone has used it and it looks very simple ,but i cant find any thing on the internet that says how affective it is not just for warmth but also for noise ?

Thanks in advance

And a Happy New Year to you all

Sarah J

 

[Flyfisher]

Have a look at: http://www.magneglaze.co.uk/what.htm. They provide some U-values for heat loss reduction and dB for sound reduction, although I think you'd need to be an acoustics expert to decipher the dB graph. it looks like a large air-gap (100mm) is really required for significant noise reduction. There's also a FAQ page that might help. There are also other company websites out there with similar information.

I've no idea if this is accurate info and I've no knowledge of the company in question, it was just the first thing I found.

 

[MdB]

As Flyfisher says, a large air gap is required for sounds proofing but a smaller gap is need for best heat performance. You can't therefore do a great job of both at the same time unless you go for tripple glazing.

 

[Feltwell]

Was this the thread you are referring to Sarah?

http://periodproperty.co.uk/forum/viewtopic.php?f=1&t=10068&p=128391&hilit=magnetic#p128391

There's been a few. 'Twas I that did the window at the end, I confess I haven't done any more since then as I've been distracted with other things. That window has the most horrendous gaps round the opening section - you can see daylight through them, no problem, and due to the design of the window it's not easy to draughtproof.

The secondary glazing has definitely made the room warmer, but that's more due to stopping the draught than anything else. The perspex did come unstuck once during a gale that was blowing directly onto that wall, but the perspex didn't fall down - merely became detached at one corner, which was enough to relieve the pressure build-up behind it I guess. Other than that it's been fine.

It does seem to reduce the noise from outside quite a lot, although as it's only an en-suite bathroom it's not a room that we spend long periods in.

Worth doing? Yes, I'd say so, I certainly intend to carry on and do other rooms.

 

[Penners]

An acoustic engineer once told me that effective acoustic insulation requires - as has been said - a gap of at least 100mm between the two glazing "leaves". The acoustic attenuation is also improved if you line the void between the leaves with acoustic tiles.

Feltwell, when you used the magnetic system on your "test" window, did you also consider - and reject - the Easyfix system? If so, what were your reasons for preferring the magnetic kit?

 

[Feltwell]

Feltwell, when you used the magnetic system on your "test" window, did you also consider - and reject - the Easyfix system? If so, what were your reasons for preferring the magnetic kit?

Just aesthetics really Penners. The Easyfix system relies on those turnbuckle type brackets, and if I remember rightly you put an edging strip on the perspex. I thought dirt would eventually get under the edging and make it look a bit unsightly - plus the brackets are visible all year round. With the magentic system, the steel tape you stick to the window is very thin indeed, once over-painted I think it will be practically invisible in summer when I take the perspex down.

Functionally, I expect they are much the same - and the aesthetic element is personal preference, others may disagree and feel the Easyfix is less intrusive.

The only niggling doubt in my mind was that my parents had a system simiar to the Easyfix many years ago, eventually the brackets went brittle and started to break. Plastics have come on a long way since the 70's though, so maybe not so much of a problem now.

 

[Feltwell]

Forgot to say - this firm's method is almost certainly better than the one I used, as it is magnet-to-magnet, rather than magent-to-steel - so they should stick better. But it is considerably more expensive, which is why I didn't use it.

http://www.magneglaze.co.uk/index.htm

 

[Penners]

That's all very useful, Feltwell. Many thanks.

Did your view of the cost of Magneglaze take account of the fact that they supply the acrylic sheet as well as the magnetic fixing system?

 

[Feltwell]

The cost from the Magneglaze website is £100 - £120 per m2, but that's for installed - for DIY you get 25% off. I put a quote for a single 1000 x 1000mm panel in to their online shop, and it came out at £75 inc VAT + delivery.

The Magneglaze site doesn't state what thickness Perspex they use, but to compare, a single sheet of the same material in 3mm thickness cut-to-size to 1000 x 1000mm is £20 inc VAT + delivery from these people:-

http://www.theplasticman.co.uk/index.php

You've then got the cost of the tape kit on top - £35 for 30m of tape, so as our example above would use 4m that's about £5:-

http://www.magnetick.co.uk/gbu0-prodshow/diy-secondary-glazing-magnetic-double.html.

So, very roughly, the Magneglaze option is about 3 times the price of the DIY option I used - but it does look to be a better product.

 

[sarah j]

Thanks for all your answers .....sorry for the delay in reply snowed in and no electric till now :? window do look pretty covered in ice though :lol:

thanks again