Minera Roof Trusses can provide your project whether large or small, to site, in 5 working days nationwide in the UK, for roof trusses, attic roof trusses and engineered floor joist - open metal web ( Ecojoist / Posi-Joist / Easi - Joist ) 35 years specialists in the design and manufacture of roof trusses and engineered floor joists - open metal web ( Ecojoist / Posi-Joist / Easi-Joist ). Free design and quotation service. Delivery of roof trusses & joists in 5 days.