Meranti vs Sapele wood windows

NJG_2

Hi,

We're having new double glazed sash windows. I was recommended to go with Sapele hardwood and have been getting quotes accordingly. We've narrowed down to two joineries and our preferred one has now said the windows will be made from meranti and has recommended this for windows, saying that sapele is better used for things such as doors.

I've read mixed things about meranti, some good some bad.

Can anyone shed some light here?

Furts

I obtained a sample piece of Sapele from a reputable trade timber supplier. This was for use as window cill boards. The sample received coats of varnish and was left on a window cill for a couple of months to give it a suitability test. The sunlight bleached all the pink natural colour out of the timber. The Sapele seemed like Balsa wood - porous, soft, and light weight. Obviously tougher than Balsa but as a "hardwood" I was left unimpressed.

So the Sapele was not ordered - the client would not accept the bleached appearance. Based on this, albeit limited, experience I would not consider Sapele for windows.

leveller2911

Furts wrote: »

I obtained a sample piece of Sapele from a reputable trade timber supplier. This was for use as window cill boards. The sample received coats of varnish and was left on a window cill for a couple of months to give it a suitability test. The sunlight bleached all the pink natural colour out of the timber. The Sapele seemed like Balsa wood - porous, soft, and light weight. Obviously tougher than Balsa but as a "hardwood" I was left unimpressed.

So the Sapele was not ordered - the client would not accept the bleached appearance. Based on this, albeit limited, experience I would not consider Sapele for windows.

Furts, Either you had been given the wrong sample of timber or it was labelled incorrectly and they were mixed up. The symptoms your describing are typical of Meranti. Sapele if far denser,harder,heavier and more durable than Meranti.. Meranti is a pale reddish in colour verying on pink ,its grain is like straw,its a lot lighter in weight than Sapele and its less durable... There are only 2 reasons why people use Meranti in joinery,firstly its a bit cheaper and secondly its easier to machine so it doesn't blunt the tooling in the same way that Sapele does.Sapele is as shock resistant as Oak ,its grain is shorter whereas Meranti has a longer grain structure and goes like straw after a few years, very bad idea to use it for door/window sills.

I would never recommend Meranti....... Sapele will outlast Meranti by a good few years.

http://www.trada.co.uk/techinfo/tsg/view/55

http://www.trada.co.uk/techinfo/tsg/view/89


Most builders merchants will stock door sills,windows sills etc that are made from meranti rather than Sapele ,mainly due to marketing as they can advertise it as "Hardwood", which it is but its a fairly cheap one and not very durable.Most timbers will fade if left in the sun for weeks if it was treated with a clear varnish or oil. The UV protection in a product is in the colour pigment so a clear finish will fade quicker than a stain if exposed to the light for any length of time.

Furts

leveller2911 wrote: »

Furts, Either you had been given the wrong sample of timber or it was labelled incorrectly. Sapele if far denser,harder,heavier and more durable than Meranti.. Meranti is a pale reddish in colour vering on pink ,its grain is like straw,its a lot lighter in weight than Sapele and its less durable... There are only 2 reasons why people use Meranti in joinery,firstly its a bit cheaper and secondly its easier to machine so it doesn't blunt the tooling..

I would never recommend Meranti....... Sapele will outlast Meranti by a good few years.

http://www.trada.co.uk/techinfo/tsg/view/55

http://www.trada.co.uk/techinfo/tsg/view/89


Most builders merchants will stock door sills,windows sills etc that are made from meranti rather than Sapele ,mainly due to marketing as they can advertise it as "Hardwood", which it is but its a fairly cheap one and not very durable.Most timbers will fade if left in the sun for weeks if it was treated with a clear varnish or oil. The UV protection in a product is in the colour pigment so a clear finish will fade quicker than a stain if exposed to the light for any length of time.

Thanks for this- it sets me thinking. I do not have the sample to hand and do not know where it went. The supplier was Timbmet - they had, IIRR, American Oak and Sapele in stock, machined for cill boards. Hence there was a sample of both forwarded. The varnish coats were plentiful, traditional oil based highish VOC, and what the client had specified. There was no comparison between the two samples for density - the oak was in another league.

leveller2911

Furts wrote: »

Thanks for this- it sets me thinking. I do not have the sample to hand and do not know where it went. The supplier was Timbmet - they had, IIRR, American Oak and Sapele in stock, machined for cill boards. Hence there was a sample of both forwarded. The varnish coats were plentiful, traditional oil based highish VOC, and what the client had specified. There was no comparison between the two samples for density - the oak was in another league.

European Oak Joinery grade is a premium, the only timber we can get thats more expensive is Teak and that is 3x the price of Oak......:eek:

I've never had much luck with Timbmet, we have a small workshop with 2 of us and Timbmet weren't interested in supplying us so we haven' bothered to use them since. Brooks Bros UK are ok and Y Goldbergs are excellant in service and quality. From your post Furts it definately sounds like it was Meranti you had trouble with.

The only timber lighter in weight that we get over here is Brazilian cedar which is very good for windows, very stable but its soft and can damage easily so we tend to use Sapele and sometimes Douglas fir.

makeyourdaddyproud

I can confirm that sapele is a superior hardwood. As an earlier poster said, it IS indeed very tough, tough on tooling and will last a very long time. I have about 35 sash windows in my period house and all repairs were done with sapele. It is true that the closer the grain the longer the gain.

It is, however, expensive.

ryder72

Interesting point leveller2911 - Would you recommend use of Meranti window frames for triple glazed windows where the outside is aluminium capped? Externally the wood frame itself is going to have minimal-no exposure to the elements whereas internally they would be painted/stained.

I have looked at options and the supplier in question only offers UPVC and Aluminium. I dont like UPVC and Aluminium is pretty poor from a thermal bridging perspective so its going to have to be timber.

Thanks

Furts

ryder72 wrote: »

Interesting point leveller2911 - Would you recommend use of Meranti window frames for triple glazed windows where the outside is aluminium capped? Externally the wood frame itself is going to have minimal-no exposure to the elements whereas internally they would be painted/stained.

I have looked at options and the supplier in question only offers UPVC and Aluminium. I dont like UPVC and Aluminium is pretty poor from a thermal bridging perspective so its going to have to be timber.

Thanks

Timber windows capped with aluminium, or upvc, is in my humble opinion a flawed design concept. There has been an importer promoting American windows of this nature at Self Build shows over the last ten years - albeit not Meranti. Regardless, I regard timber as a natural product that needs to breath, and vary its moisture content in accordance with the atmosphere. Sealing windows with aluminium is no different to tacking upvc to existing fascias, thus encouraging the original fascia to sweat, condensate and rot even quicker.

Further, for this design concept to work there must be meticulous attention to detail with the finish and atmosphere within the room. Then the external capping should be meticulously vented. In other words, the construction should follow the principles of timber frame building. I cannot comment on the windows in question, but my concern is that such windows do not conform to this.

If one thinks of commercial developments such as office blocks, or private appartments in Canary Wharf, they invariably have aluminium windows, for a reason!

ryder72

Hi Furts

I used alu capped windows too losely and I agree with the point you make.

These are the windows in question - http://www.kowa.de/fenster/fenster_holz_aluminium#line_

You can see the external frame is alu and the internal wood. They have quoted in Meranti as their preferred product but offer other options too.

Your thoughts?

Furts

ryder72 wrote: »

Hi Furts

I used alu capped windows too losely and I agree with the point you make.

These are the windows in question - http://www.kowa.de/fenster/fenster_holz_aluminium#line_

You can see the external frame is alu and the internal wood. They have quoted in Meranti as their preferred product but offer other options too.

Your thoughts?

The devil is in the detail. Just scimming quickly at the web page makes me ask some questions.

I suggest the external surround should receive venting - what provision is there for this? Plus how is it sealed to the construction opening?

Of greater concern is that the cill design and construction are incompatible with UK building practice for new build and it could be argued for refurbishment too.

Then one has to consider where the window is located within the wall. This is for protection, from exposure and for insulation,

Then one has to consider if the proposed use in in an area of exposure. Here different construction rules apply - do a search on checked cavities and these windows may not conform. Even outside these exposure areas good practice may mean checked cavities.

Basically your window company would be prudent to draw up construction details applicable to your proposed location. Perhaps they have already done this?

leveller2911

Furts raises some good points that should be looked into but looking at the designs they look pretty good to me as long as the Aluminium clad prevents any water ingress reaching the timber.I would imagine this is mostly done with gaskets. I would imagine they would give at least a 10-15yr guarantee on the finish,workmanship and rot. If theres no way water can reach the timber then it really doesn't matter which timber you chose. The "Globolus" one is actually Eucalyptus and its not uncommon for UK Joinery workshops to use it.


They all seem to open inwards which is common in Europe where the window reveals are designed specifically for it so you may need to me aware of limitations around inside of the windows with furniture etc. Modern paint finishes/Powder coatings have advanced and are very good but I do have concerns on how long it would take for the colour to fade,which it will.

One thing, I personally wouldn't bother with is the triple glazing if its optional. It costs a premium for little benefit. As an example , a decent double glazed unit will have a U value of 1.1 and the triple glazing has a U value of around 0.7 so that saving of around 0.4 is saving you a few pence a year and you lose more light with triple glazing, 3 panes of glass will let in less light than 2. For me triple glazing just isn't worth paying the premium. If you're replacing existing windows then the windows need to have a U value of 1.5 or below.

One question to ask is how easy is it to replace a failed sealed unit?. If its just a matter of replacing similar to Upvc with a beaded gasket its not a problem ,if its fully bonded it could be a pain.

If you have a modern contemporary property Alu clad would look good...