U.S. homebuilder sentiment fell for the third consecutive month in April, with builders citing increasing materials costs and supply chain concerns, the National Association of Home Builders (NAHB) said Monday. The NAHB/Wells Fargo Housing Market index dropped to 42 from 44 in March, which was shy of economists’ expectations of 45. The index has not been above 50, which signals that more builders view market conditions as favorable, since April 2006, when the housing market collapse was taking hold. Still, the index staged a strong comeback in 2012 and is 18 points above where it was a year ago. “Supply chains for building materials, developed lots and skilled workers will take some time to re-establish themselves following the recession, and in the meantime builders are feeling squeezed by higher costs and limited availability issues,” NAHB chief economist David Crowe said in a statement. The single-family home sales component fell to 45 from 47, while prospective buyer traffic eased to 30 from 34. Still, the outlook for the coming months was more optimistic as builders pointed to low inventory and mortgage rates, and improved consumer confidence. The gauge of single-family sales expectations for the next six months rose to 53 from 50.