Leave the M1 at junction 8, then merge onto the A414 (signposted Hemel Hempstead). At the roundabout take the 2nd exit onto the A414 (signposted Hemel Hempstead).At the next roundabout take the 3rd exit onto the A4147 (Maylands Avenue, signposted Redbourn B487). Continue along Maylands Avenue for approximately 1 mile, Screwfix is on the right hand side of the road (visible from Maylands Avenue).