Replacement Sash windows - which wood?

maharani

Hello,

I am replacing my sash and case windows with new double glazed timber windows. I have had 2 quotes; one for treated redwood and the other for Majau which seems to be a species of meranti. I am having 4 windows made and the quote for redwood is £4200 and Majau (meranti) is £5000. I have done some research and it seems that the Majau (meranti) may be from a dubious source but it is a hardwood so should me more durable?

Would like some opinions on which option is best both for durability and sustainability...

Thanks!

leveller2911

I'm not a fan of treated Redwood purely because its not very stable compared to other timbers.I'm interested to know how its treated exactly?.Is it pressure treated(vac-vac,protim) or just sprayed,brushed or dipped.

Meranti is a cheap hardwood(pink in colour) ,its very light in weight and is only marginally more durable that Redwood(pine).It machines easily and doesn't blunt machine tooling so thats a financial benefit to companies who use it.Personally I prefer to use Sapele which our supplier imports from the D R of Congo.Its a member of the Mahogony family,is more durable that Meranti or Redwood,its a close grained heavy timber which if painted regularly will last for 35-75 years.Its downside if you can call it that is that it can blunt machinery cutters when making the windows.It also takes a paint finish well.

Another durable Hardwood is Iroko, again African, when cut it can be yellowish in colour but goes a dark chocolate brown when it oxidises.Downside is it can bleed through paint so needs sealing properly.Another fairly decent Hardwood is Idigbo, African again,pale in colour and cheaper than Sapele and Iroko.Downside is it can warp and twist. All these can be obtained from good timber importers who can trace the timber from its source.

For me its : 1/ Sapele 2/Iroko 3/Idigbo 4/Meranti 5/Redwood (last resort)


My top choice would be Sapele and also Brazilian Cedar( but its difficult to get hold of in large quantities)..

Russe11

I'd say Sapele also if painted.

Best paint finish/longest lasting I have seen is a 3 part range, name is not fixed in my mind but it consists of a oil, then adhesion primer, then undercoat all before the topcoat.

Aluminium primer also seems to be specified a lot by archiects I know, must be more durable.

Whatliesbeneth

Have you thought about having the windows repaired and upgraded with double glazing. these people do this might be cheaper than having them replaced.

ventrolla.co.uk

sashman

leveller2911 wrote: »

.Downside is it can warp and twist. All these can be obtained from good timber importers who can trace the timber from its source.

To prevent warping and twisting you can consider engineered timbers, also known as laminated wood as these are more stable.

Don't forget FSC approved http://www.fsc.org/ the wwf said the uk is the third largest importer of illegal timber!

Sashman

leveller2911

sashman wrote: »

To prevent warping and twisting you can consider engineered timbers, also known as laminated wood as these are more stable.

Don't forget FSC approved http://www.fsc.org/ the wwf said the uk is the third largest importer of illegal timber!

Sashman

I only deal with companies who can trace their stock from source. I have used Laminated Oak on staircases which is ok but you can get colour variation where the timbers are glued up which isn't great.Its fine if its going to be painted.
It would be interesting to see how laminated timber holds up over time, because its a fairly new thing no one really knows if it can/will de-laminate in say 20 years time.

sashman

leveller2911 wrote: »

I only deal with companies who can trace their stock from source. I have used Laminated Oak on staircases which is ok but you can get colour variation where the timbers are glued up which isn't great.Its fine if its going to be painted.
It would be interesting to see how laminated timber holds up over time, because its a fairly new thing no one really knows if it can/will de-laminate in say 20 years time.

Sweden has been using for at least 30 years massive roof spans etc

leveller2911

sashman wrote: »

Sweden has been using for at least 30 years massive roof spans etc

Do you mean gluelam beams? if so I think they only use them where they are protected from the elements........ So thats not the same thing as laminated timber used for Joinery AFAIA.........


The main reason companies sell laminated timber is because they generally use what looks like offcuts.Its basiclly a way of using as much of the timber as possible.

I guess its ok if its going to be painted but if the customer would like the product stained or oil just imagine what it looks like with lots of glue joints, it would look hideous .I guess I'm old fashioned in that I like to see nice figured grain......