DEPENDS ALOT ON THE TYPE OF MATERIAL. I HAVE A SHAPPEL 3000 THAT IS A SYNTHETIC CANVAS. I HAVE REPAIRED IT SUCCESSFULLY BY FIST SEWING THE TEAR AND THEN USING IRON-ON DENIM PATCHES. THE REPAIRS HAVE LASTED SEVERAL YEARS SO FAR.
If it is canvas, Cabela's sells a patch kit for boat covers that works very well. Cut to fit material and adhesive- got three extra years out of my boat cover and the patches never even tried to lift off.
you can get repair patches for tents and back packs from good camping stores like REI and just match up the weight of the patch material with the weight of you hut material most are self adhesive or iron on but i would recomend sewing round the edges for a more durable job
i see that we are not the only ones that just can't seem to go wrong with usl(the company that make the calm's and fish traps) they just make and service a better product, definetely not the cheapest but in my opinion probably the best. i have owned 3 usl shelters and they all kicked a$$