"The great thing about the coffin business is it's been a question of the market coming to us, but with the furniture it was always a question of us saying 'We've got this, do you want it?'."
The coffins got an unexpected advertising boost last summer when Nicholas Albery, a prominent environmentalist campaigner, was buried in one after being killed in a car crash.
Mr Albery was the founder of the Natural Death Centre, which promotes burials in woodland rather than cemeteries and "inexpensive, green, family-organised funerals".
Mr Wainman set up his small factory in the central Chinese province of Hunan about seven years ago after becoming fascinated by bamboo during a year spent teaching English in the small city of Changde.
"I had an idea in my mind that it was a fairly environmentally beneficial material - in fact, it's even better than I'd imagined it could be," he says.
Bamboo never needs replanting, it grows back rapidly after being cut - up to a metre a day for some species. It is strong, pliable, with greater tensile strength than steel, and produces more oxygen than any other plant for its size to weight ratio, he enthuses.
But his environmentalist beliefs were not the only reason Mr Wainman wanted to start a business in Hunan. He had fallen in love with Zhang Weimin, now his wife.
"I wanted to go back to the same sort of area but I found the only way I could do that was to create my own employment - the only international companies were all in Beijing and Hong Kong."
Changde is a poor place - a farming area where the average income is about 500 yuan a month ($60; £42).
Local officials welcomed his plans, but that did nothing to lower the bureaucratic hurdles to starting a company. And China's WTO entry is unlikely to reduce the number of regulations.
"They still had numerous rules and regulations to follow to the letter, and to make sure that I followed to the letter," he says.
It took three months to collect half a dozen company licences from different government departments, while his UK company licence took just 24 hours.
Weiming Furniture - named in honour of his father-in-law, who is now his export manager - employs about 35 staff in China, has a small office in Britain and annual sales of just under £100,000 ($145,000). Coffins account for more than half of that.
Weiming's workers are mostly part-time subsistence farmers aged over 50. Just like elsewhere in rural China, younger people prefer to seek a more prosperous life in the urban fast-lane.
China's low wages have been a major attraction for manufacturers, building its reputation as a cheap assembly point for consumer goods. Subcontracting work among small rural factories can be cheapest of all. But Mr Wainman is anxious not to be seen as a low-wage employer.
The next stage in his business plan involves the sort of workers co-operative which is increasingly rare in China's drive towards a market economy.
The biggest obstacle to his profit-sharing scheme is his local Chinese partner: "I think he will come along...it's just a question of explaining everything very carefully to him." The coffins are cheaper than more conventional caskets - so he is confident they have a wider market.
He expects China's entry into the World Trade Organisation to change little for him.
"Hopefully our type of goods is not one that would be involved in a tariff war. That's one advantage of being quite small and in a niche market".
Bamboo has nothing but a positive reputation when it comes to the environment. It grows quickly, it doesn't need pesticides or much water, it pulls carbon dioxide out of the air, and it can be used in a nearly unimaginable range of products. With its well deserved, eco-friendly reputation, companies have been quick to integrate bamboo into product lines and new bamboo-based businesses continue to pop up.
There are now bamboo shirts, skirts, socks, underwear, furniture, floors, paper, plates, sheets, towels, plates, bowls, spoons, kitchen utensils, keyboards, cleaning wipes and of course coffins...practically enough items to outfit an entire house made with bamboo everything.
Method, the San Francisco-based cleaning-products company, uses bamboo for cleaning wipes, aroma rings as well as some of its packaging. And Totally Bamboo, a southern California-based company, sells more than 300 different bamboo-based products.
But with great demand comes the need for great supply. As more and more companies look to source products using bamboo, unsustainable harvesting methods may end up killing a resource that has so much potential.
One downside of bamboo's popularity is that it's at risk from overharvesting: The United Nations warns that about half of the 1,200 varieties of bamboo in the world are extinct or in danger of being eradicated.
Enter BooShoot Gardens, a plant tissue culture laboratory out of Mount Vernon, Wash., that is growing large amounts of specific types of bamboo to replenish and increase the world's bamboo supply and meet the demand from companies like Method and Totally Bamboo.
Founded in 1998 by Jackie Heinricher, BooShoot produced 2,000 bamboo plants in 2004, the first year it released plants. This year it plans to produce more than 2 million, and has the capacity to produce 12 million.
The company sells its bamboo through wholesale growers and retailers in more than 20 states and Canada. It's been selling bamboo to a biofuel company in the southeast U.S., projects in South Africa and throughout Southeast Asia.
What's Driving the Bamboo Market
Bamboo has such a green reputation because it grows fast (earning it the moniker of a "rapidly renewable" resource as opposed to a plain old "renewable" resource, a title given to everything from trees to corn to chicken feathers), doesn't require pesticides, uses little water, and pulls carbon dioxide out of the air faster and better than other plants.
Bamboo plants sequester four times as much carbon dioxide as hardwood trees (taking in 62 tons of CO2 per 2.4 acres versus 16 tons per 2.4 acres of trees) and puts out 35 percent more oxygen.
While bamboo has been recognized for quite a while as a green material, its use has shot up in the last few years along with many other green materials. Bamboo goods are proliferating at major mainstream retailers like Wal-Mart and Target, and being used in clothing both from eco-centric companies and more mainstream ones like JCPenney and Banana Republic.
The bamboo goods industry is expected to be worth $25 billion around 2012, Heinricher said, and some companies that make or are looking into making bamboo goods are encountering a supply bottleneck.
While this demand is boosting BooShoot's business, it's having a handful of negative effects on the global bamboo supply. As demand has increased and supply tightened, the final products have been affected. Bamboo flooring, for example, is generally much thinner these days than years ago, Heinricher said.
And then there's the rate of harvesting: Bamboo can be harvested every 5-10 years, much faster than trees used for other forest-based products. But harvesting is starting to outpace bamboo growth and its ability to recover. Cutting down too much bamboo in one area can damage an even-wider stretch of the plant.
If more than 30 percent (of an acre) is taken at any one time, it begins to affect the viability of the root system and begins to compromise bamboo's ability to replenish itself.