hey im gordon

i have a 1 year old red tailed boa and was wondering if any1 can help me. Firstly i am constructing a quite large home for my snake and need 2 know what sort of material i can buy in powder form 2 make the walls like a rock face ???? i know ther are harsh chemicals in concrete and other sorts of things like that and would never dream of using these unless i new they wer 100% safe for her 2 clime on. any help??? plz get back 2 me asap she needs this new home fast as she never stops growing lol. G