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Interior timber & flooring

Like to know what wood to use building a pergola or framing a barn? How about the difference between tung oil and polyurethane as a floor finish? How to revive decking or deal with merbau stains? Or how to meet the building code or bushfire standards? Or ask about the environmental advantages of wood or forest certification?

Q. I am an architect specifying a timber board ceiling. Board widths are approximately 85mm and I want the longest lengths possible. It will be painted white. Would I do it in Western Red Cedar or is there something more appropriate/cost effective, as I am going to paint it white? The ceiling then extends to the outside. What timber should I use externally? It will also be painted white.

The advantage of using western red cedar is that is relatively dimensionally stable with little tendency to swell, shrink or twist when undergoing changes in moisture content. So although it will be painted in this project, cedar is still a good choice, particularly where the linings extend to the outside. Even with a cheaper timber the labour component to install it is the same, so it wouldn't make a dramatic difference to the in-place cost. One point to watch - painting only the exposed surface could lead to cupping, since the unsealed surface may absorb moisture from the air during humid weather while the painted surface won't, especially in the outdoor area. So we recommend a sealer coat on the backs of the boards before they are installed.

Q. What is the maximum span for 12mm x 140mm VJ Baltic pine lining boards for a ceiling with R7 batts on top? Nails will go directly into the face of the boards (not secret nailed). What size brad nails for 900 span if 900 is acceptable?

The usual recommendation for pine ceiling lining is that 12mm boards should be supported at 600mm centres while 19mm boards can span 1200mm. This assumes the lining boards are installed at 90° to the fixing battens or joists. Spans are reduced if the boards are fixed at 45°. A typical producer's installation instructions can be found at this site: http://www.chhwoodproducts.com.au/userfiles/5/File/Smartfinish_PDF.pdf. These recommendations are aimed at restraining any potential movement during changes in the weather, ie. exceptionally dry or humid spells.

Q. My partner and I currently have indoor concrete steps that we are looking at putting timber treads on. We would like to know if Claymark Premium Radiata Pine in 19mm would be suitable for this purpose?

We understand that Claymark Premium radiata pine is "clear" pine, ie. knot-free. It would therefore be quite an attractive product, although rather plain. Maybe you could view some samples before making a decision. While pine stands up relatively well to general wear it is at the softer end of the spectrum and will dent under high-heeled shoes. If this kind of foot traffic is unlikely, pine should give satisfactory service with a suitable finish, eg. flooring-grade polyurethane.

Q. We have jarrah timber floor, ghosting patches appearing in front of window, do we have to re-sand? Rather not, any other soloution? Please help, only 3 years old.

Ghosting is described in a special data sheet prepared by the Australian Timber Flooring Association (ATFA) - for more detail, paste this link into your browser: http://www.atfa.com.au/downloads/42_Ghosting.pdf. The causes are not fully understood, although some fairly likely explanations are given in the data sheet. It's suggested that sanding back to bare wood will usually correct the problem. Since you understandably don't want to re-sand a new floor it might be worth trying the technique of removing heat marks from timber, using a warm iron over a damp cloth, or an iron set to steam. No guarantee that it will work on ghosting, but it certainly works on heat marks - we've tried it! For more information visit this site: http://tipnut.com/diy-how-to-remove-white-heat-stains-on-wood-table/. And if it does work, let us know.

Q. My query is this. We put masonite and vinyl down over a pinewood flooring in the kitchen/family room 34 years ago. We are now renovating the kitchen and considering pulling up the flooring and sanding and putting estapol on the pinewood flooring. I've read that pinewood would have softened over the 34 years and therefore would now not be as durable. Also, the masonite would have been nailed to the floor so there'd be a whole lot of nails to fill in and sand back thus further weakening the floor, I'd imagine. Would you be able to confirm this information for us. We have also knowledge that vinyl put down before 1985 could have a certain degree of asbestos in it and therefore would require a specialist to remove it. I know that's not along your line of advice, but wondering if you have any knowledge to offer.

Pine flooring won't be any softer now than it was when installed, unless it is damp. Assuming the sub-floor ventilation is OK your flooring should be fine. Nevertheless it is one of the softer timbers and therefore may be dented if people walk on it in high-heeled shoes. Other than that it will stand up to normal wear, but we would recommend mats in high traffic areas and places such as under table settings where chairs could be pulled in and out. Nail holes can be filled so as to be inconspicuous, but there may be gaps between boards if any shrinkage has occurred. We don't recommend filling these gaps as the filler tends to work loose, so you might want to have a careful look at a small area before you start pulling up all the vinyl, to make sure the floor is in a satsifactory condition. We don't have any expertise on asbestos removal but there's an informative data sheet available on the net at this address: http://www.deir.qld.gov.au/workplace/resources/pdfs/asbestos_factsheet4.pdf.

Q. A client has a 1950s/possibly 60s holiday shack. The current flooring is 12mm particle board nailed into t and g boarding, which all looks pretty sound from underneath and the subfloor is very well ventilated. I can’t determine whether it was always this way or if the particleboard was a later addition. The client wants to lift the particleboard and replace it with 12mm t&g hardwood strip flooring from recycled hardwood. 1) Do you foresee any problems? 2) How is it best to fix it- glued or nailed across the existing boards or running with the existing and nailed through to the joists under?

A data sheet prepared by Timber Queensland answers your question as follows: "Timber T & G flooring may be laid over existing T & G or sheet floors (plywood or particleboard). Where the existing floor is structurally sound, either overlay flooring (generally 11 mm to 14 mm thick) or structural flooring (generally 19 mm to 21 mm thick) can be laid. Floors may be fixed into the joists or with shorter fixings at reduced centres into the existing floor only. In instances where there is doubt over the structural adequacy of the existing floor, defective boards or sheets should be replaced to make the existing floor structurally sound, or structural flooring fixed through to the joists can be used. To provide a level surface, top (face) nails in existing flooring should be repunched and the existing floor rough sanded. Adhesives require a clean, structurally sound floor that is free from moisture, loose particles and contaminants. It is also particularly important that if a new floor is laid at 90° to an existing floor, the existing floor must be structurally sound and level. In some instances sheet sub-floors (substrates) can sag between joists and if not leveled the sagging will show through to the new floor."

Q. I have just laid victorian ash floor boards. I had planned to have these stained in a mid grey color. The people coloring our floor have tried but all of their probs are either all Brown looking or very dark - Brown/black. Am hoping that you can suggest what type of stain to use on victorian ash that will make it a true mid grey color - not dark nor light. I have picture examples of the color level I'm after if that would help you make your recommendation.

We hope your contractors are trying out different stains on offcuts, rather than on the floor iteself. It's difficult to give you a definite recommendation but perhaps a Liming White stain would give you the look you want. You can check out an image via this link: http://cabots.com.au/product-detail/1448/stain-varnish-water-based. However, we emphasise that you should look at this product (and other products) on a piece of timber and not rely on a colour card or digital image.

Q. We have some 32mm blackbutt that we had planned to use on a wall in our stairwell (1.5 levels high). my husband is concerned that this will be too heavy even with extra battens. It's beautiful timber that we would love to use. Do you think it's possible?

It's certainly a lot thicker than the usual 12mm wall panelling, but it won't be a problem if the boards are installed vertically and sit on the floor at their base. The wall fixings then only have to stop the timber from falling over, they are not actually carrying any vertical load. If the boards stop short of the floor you will have to make sure the wall fixings are capable of carrying the load. The critical issue will be the attachment of the battens to the wall. If the wall is brickwork or blockwork, chemical anchors will provide secure fixing. If the wall is timber framed, the battens will need to be screwed through the existing lining into the studs behind.

Q. A client has a 1950s/possibly 60s holiday shack. The current flooring is 12mm particle board nailed into t and g boarding, which all looks pretty sound from underneath and the subfloor is very well ventilated. I can’t determine whether it was always this way or if the particleboard was a later addition. The client wants to lift the particleboard and replace it with 12mm t&g hardwood strip flooring from recycled hardwood. 1) Do you foresee any problems? 2) How is it best to fix it- glued or nailed across the existing boards or running with the existing and nailed through to the joists under?

A data sheet prepared by Timber Queensland answers your question as follows: "Timber T & G flooring may be laid over existing T & G or sheet floors (plywood or particleboard). Where the existing floor is structurally sound, either overlay flooring (generally 11 mm to 14 mm thick) or structural flooring (generally 19 mm to 21 mm thick) can be laid. Floors may be fixed into the joists or with shorter fixings at reduced centres into the existing floor only. In instances where there is doubt over the structural adequacy of the existing floor, defective boards or sheets should be replaced to make the existing floor structurally sound, or structural flooring fixed through to the joists can be used. To provide a level surface, top (face) nails in existing flooring should be repunched and the existing floor rough sanded. Adhesives require a clean, structurally sound floor that is free from moisture, loose particles and contaminants. It is also particularly important that if a new floor is laid at 90° to an existing floor, the existing floor must be structurally sound and level. In some instances sheet sub-floors (substrates) can sag between joists and if not leveled the sagging will show through to the new floor."

Q. Our architects are recommending blackbutt throughout our house, including the kitchen. Where I know blackbutt is OK for living and dining, I am concerned that it will not survive in the kitchen. This area is high traffic and often wet and soiled. Are there better timbers to use AND are there any treatments that we can be confident will protect these areas? Placing mats down is not an option.

A lot depends on the family's behaviour, the size and location of the kitchen, and so on. If you are already doubtful about a timber floor in the kitchen, maybe it's not for you. Blackbutt is at the harder end of the scale (harder than jarrah on average) which means it is quite resistant to dents and scratches. However, like all timber it won't perform well if it's "often wet", as you suggest it will be. Timber floors are also vulnerable with respect to the tongue and groove joints between boards where water can enter and debris can collect. An even denser timber, such as ironbark, will be slightly less absorbent but if it's going to be often wet and soiled, and subject to high traffic, the finish will have a reduced life, needing re-coating more often. We have seen timber floors perform relatively well in kitchens where the occupants mainly wear rubber-soled shoes, there are no small children, and spillage is minimal. However, this doesn't sound like your situation. In your case perhaps a tiled floor would be a better option, since it can be wet mopped frequently without causing harm.

WoodSolutions

Did you know?

Australia’s native forests, timber plantations and wood products are net absorbers of greenhouse gases, sequestering 56.5 million tonnes of carbon dioxide in 2005, reducing Australia’s total greenhouse gas emissions by nearly 10%.