What kind of timber?

[Deleted2797112]

I have a garden bench in need of restoration. It's one of the traditional sort with swirly cast iron ends and timber slats. One (maybe more) of the 12 slats has rotted at the ends and needs replacing. Does anyone know please which timber is generally used for these? It must be some kind of hardwood but I have no idea where to start. Also, how best to treat the timber? Is it OK to oil something you sit on?

 

[Burnerman]

Ideally the timber should be teak, oak or some other quality hardwood.....in reality it rarely is!
Tanalised softwood would be ok for the cheaper option - the colour (greenish) can be toned down to some degree with a Sadolin garden furniture treatment or similar, and its best to plane it smooth.
I guess it depends on what sort of timber you can get, and how much trouble you want to go to.....a timber yard could fix you up with some hardwood strips of oak or mahogany etc.
The ends of the slats are sometimes bolted down with roofing bolts - you may need to cut these away if they wont unscrew. Other makes use traditional wood screws - brass or stainless steel being best.
John

 

[Deleted2797112]

Thanks - that's great! I'm pretty sure the current slats are a hardwood judging by the weight and denseness of the grain so I think the oak or mahogany option is the way to go.

I did wonder about the bolts. The bench is quite old and neglected (was here and in that condition when I bought the house) but the bolts on the top side are bright and shiny steel, almost look like chrome with no obvious rusting or corrosion. The head is flat and rounded with a slot but doesn't look like a normal wood screw head to me. I just googled some images of roofing bolts and I think it's probably those except there is only a single slot rather than the cross. I've no idea if they'll budge or not!

 

[Burnerman]

Commonly the bolts used on these are short roofing bolts - maybe with a cross slotted head or just a single slot. They are plated to help prevent corrosion and the nuts were frequently square.....unfortunately the depth of the screw slot prevents good purchase with a screwdriver so its best to grind the nuts off with an angle grinder.
Of course you can fit fewer but wider slats if you prefer - it depends what timber you can find. B&Q etc supply the bolts.
Enjoy!
John

 

[Deleted2797112]

Yes, that's them. Great tip about grinding the nuts off - thank you! I thought the slots looked quite shallow.

 

[r896neo]

I wouldn't use oak its open grain makes it much rougher in texture and it will go green quicker.

Iroko is probably a good bet it is essentially the modern version of teak which is now very hard to get but has the same oily texture which makes it long lasting outdoors.

Any of the outdoor decking timbers like western red cedar, balau etc would also do.

Very important is the stretcher bar at the base as it keeps it stiff and must be done in metal not a piece of timber.

 

[Deleted2797112]

Thanks for that, iroko sounds just the ticket. I'm hoping I might just need to replace one slat, on quick inspection the others look quite sound but very wet. I've been wrestling with it this afternoon and managed to get all but 3 slats off before the light went - hard work, I don't have a lot of hand strength or body weight to get behind the screwdriver! I've WD40'd the remaining bolts and will have another go tomorrow.

Can I ask about the stretcher bar please as I'm not sure it currently has one? Bolted into the two metal ends are diagonal metal braces that are screwed into one of the seat planks on the underside. The diagonals extend maybe one third of the way towards the centre. These I think are original to the bench. Then in the centre of the back/underside is a narrow metal strap which runs vertically and is screwed into the centre of each slat. I suspect this might be a later addition. I can't see any indication that there was ever a metal stretcher.

I took a couple of pics before I started dismantling it, I'll post them up later.

 

[Burnerman]

Iroko will certainly last for ever (used for laboratory benches) but if its cut from a large plank then it will warp like hell
Your bench sounds like a typical B&Q type one - cast ends, green or black, diagonals to the central slat from each end.
The stretcher bar is in the centre underneath and behind the slats and helps keep the spacing correct. These bits are just bent mild steel and pretty feeble really, but they all help to strengthen the structure when it is complete.
John

 

[r896neo]

if you have the diagonals then a stretcher is notreally needed. they do the same job

 

[Deleted2797112]

Iroko will certainly last for ever (used for laboratory benches) but if its cut from a large plank then it will warp like hell
Your bench sounds like a typical B&Q type one - cast ends, green or black, diagonals to the central slat from each end.
The stretcher bar is in the centre underneath and behind the slats and helps keep the spacing correct. These bits are just bent mild steel and pretty feeble really, but they all help to strengthen the structure when it is complete.
John

Hmm. I guess not iroko then as it would have to be cut from a plank I think. It's only one very narrow slat so far. There's no warping on the existing slats.

Your B&Q comment made me check their website and they don't have it but Homebase have one that looks identical here. Annoyingly it's just listed as hardwood with no further info.

Here's mine:

View media item 72611
View media item 72612
Thanks for clarifiying re the diagonals, r896neo. One less thing to worry about!

 

[Burnerman]

The steel strip (bottom pic, centre) helps to keep the spacing of the slats stable......you could do without it if you wanted to.
Anyway, the definition of 'hardwood' literally means anything that isn't in the pine family, and these benches are sourced from who knows where.....replace the slat with whatever timber you can get, and consider the Sadolin range of wood treatments. They are as good as you can buy.
When I did a similar one, I increased the slat thickness and lengthened the bench by 100mm, using second hand oak. Thats what the punter wanted!
John

 

[r896neo]

Someone told me that after contacting them about oiling it that B and Q ones were made from roble which i had never heard of and searching seemed to say roble way just another name for american white oak which it catagorically was not. It was a reddish teak type colour.

 

[Deleted2797112]

I googled roble and found my way back to this forum with a long thread about it from a few years back. Seemed to be only one supplier of the recommended treatment for it (at an extortionate price per litre!) and it's not clear if they still sell it anyway. I think I'll just assume it isn't roble and stick to conventional treatments.

The remaining bolts have defeated me so I've posted in Tools looking for a recommendation for a cheap angle grinder. I also need to shorten a few lengths of concrete scallop path edging so hopefully someone can suggest one that won't break the bank as I'm unlikely to get a lot of use out of it.