Hi Daryush.....u can use flooring bamboo for the belly,, but it should be better if u use also raw bamboo for the belly......the bamboo must be exactly used on the belly, like its being used for the back of the bow.... the belly strip can be heat treated, to a nice caramel colore.....be carrefuul not to burn the bamboo strip....from a certain point, the bamboo gets black verry quiqly, and the bamboo is ruin....its not an easey task what u are trying to do.....dont have to much space to tiller the bow,,,so all the things must be done before u glue the bow together....u can try to pretiller the bamboo strips before u glue themm up....also u should be carrefuul to the amounth of the reflex that u want to put into a bow like this....it should not be something to severe....after the bow is all glue up, u can still make some adjustments, and even scrap the belly and the back of the bow a little....to adjust the tiller....but only a little...i wish i could help u moore, but i realy dont have to much experience with this tipe of bow...i only made one bow like this....all bamboo bow...and the bow wass made only using 2 stript of bamboo glue together...not verry complicated bow...good luck..