I have just been reading through the helpful guides associated with camping, and as a tent designer and manufacturer I would agree with everything I have read so far. Now I mainly work in good old fashioned traditional heavy cotton canvas and most of the information given applies primarily to nylon tents or the lighter canvas framed tents.
There has been a huge increase in interest in and use of heavier canvas tents for the comfort and style they provide, and so I thought I would add my 'what to look for guide' on this type of tent. The styles I am mainly refering too are the bell tents, tipis, yurts, true geodesic domes, period tents etc which are made from the heavier canvas.
There are many qualities, weights and proofing differences available on the market before we even get to colours! So lets start with weights, which in effect relates to the thickness and strength of the canvas. Standard weights are given in ounces per square yard or grams per square metre, so the heavier they are the thicker and stronger the canvas should be. It should also be noted that the weight is given for the cloth in its loomstate condition; i.e. without proofing which will make it heavier.
Weight of Canvas
Weights start at 8 oz = 250 gsm (aprox), then 10 oz 330 gsm, 12 oz 390 gsm, 15 oz 510gsm, 24 oz 800 gsm. With proofing this adds about 25% to the loomstate weight.
In practice the 12oz has become the industry standard as its the most readily available; itis strong but not too heavy and is relatively easy tohandle.
8 oz is too light for many of the larger tent applications although small one and two man tents are great in it. It is also too light to be available with a fire retardantfinish.
10 oz is mainly used for the production run bell tents with aluminium pole sets and is generally not fire retardant, although some are said to use 12 oz canvas but check whether this is loomstate or proofed weight. I have made a few tents in 10 oz but have been unhappy with the water resistance compared to 12 oz canvas, and the weight saving is negligible seeing as most of us use a car to go camping.
15 oz canvas is mainly used for longer use tentslike yurts, to help resist the long exposure to the UK weather and for marquee roofs as it is much stronger than the 12 oz.
24 oz is mainly seenin relation to the imported yurts and is extremely heavy - an 18ft 5.4m diameter yurt cover will weigh in excess of 80kg in 24 oz 800 gsm canvas!
Water proofing
All quality canvas tents will be made from pre-proofed canvas, that means it will have been proofed on the roll before being made up into tents. This means the canvas will be properly impregnated with the proofings. Canvas tents dont usually have a rating like nylon tents which have a 'hydrostatic head' rating. This is because canvas is a naturally breathable material and tested in this way they are likely to leak. However because canvas swells when wet it creates its own seal and with the pitch of the roof water runs off readily. There are many re-proofing solution available but I would highly recomend Nikwax products. British standard for water proofing should be BS. 3408: 1992.
Rot Inhibitor
Included in the proofing process for canvas there should be a rot inhibitor. The beauty of natural canvas is its feel, breathability and the knowledge that it will eventually rot back down into the soil unlike nylons. However this does mean that it need some help to resist its natural tendency to return to mother earth via mould and mildew rotting, so you can get some use out of your tent. This is done by adding anti fungal treatments into the canvas proofing. If this has not been done or done poorly mould rears its ugly head and preventative action must be taken immediately. Seek professional advice if you are suffering with this. British standard for rot is BS. 2087: 1992.
Fire Retardant
This is the tricky one and many people don't want to have fire retardants in their canvas because of the chemical issues. As a commercial tent manufacturer that sells tents designed for use with wood burning stoves and open fires, all my tents are sold with fire retardant. Many of my clients use their tents for public use and they have to have fire retardants in them for public safety and insurance reasons. In the private world I would always recomend having your tent made with fire retardants even if you dont use wood burning stoves and open fires, gas cookers and candles are the main source of tent fires, and as cotton canvas will burn at around 3 - 5mph on a still day, there is no time to react. Fire retardant canvas also protects your investment, canvas tents arent cheap particularly yurts, and as I have known of a yurt burning down in the time it took for the owner to walk to the house to collect a torch and return, I would always recomend a fire retardant finish. Please remember it is ONLY a fire RETARDANT not fire PROOF, this means the fire will go out when the source of ignition is removed and will only burn very slowly, it is intendedto give you time to escape. British Standard for fire retardancy should be BS 5438/5867 or greater.
So if you are buying a tent with a stove I would check the canvas has a fire retardant and you have documentary proof. Sorry to sound like an old fuddy duddy but I have seen too many tears before bedtime!
To summarise check the weight and proofing of the canvas of your intended purchase to ensure you know exactly what you are getting. If fire retardancy is an issue ask for a certificate detailing the proofing and its BS numbers.
If you want any help with any of the issues raised you can contact me through my ebay shop - Albion Canvas ebay shop
Good camping
Alan the tent
No comments:
Post a Comment