I have had several situations where small burning coals have blown out of the lower vent while bringing the temp up initially. In one case it burned two boards on my deck which I had to replace. I stir the charcoal before starting, and remove the ash but I still seem to get a lot of small chunks that either block the airways or a gust of wind creats a backdraft and will blow them out onto my deck. Is there a better procedure to reduce the small bits of charcoal that seem to accumulate on top of the grate? I use an old shop vac from time to time which helps but is a pain in the rear. Any suggestions?