Comb-footed spiders or cob-web spiders, are very common spiders both outdoors and indoors. They are small to medium-sized spiders. Comb-footed spiders are usually brownish or greyish. They build irregular webs in many places, including wood and stone piles and in quiet areas of buildings, such as basements. A common type of comb-footed spider found indoors is the house spider.