JHH Engineering is an independent roof testing company. JHH Engineering uses electronic integrity testing to locate problems in flat roofs that might lead to water leaks. We can certify new roofs prior to handover as well as locate leaks in existing roofs.JHH Engineering is a UKAS accredited testing labratory which means that customers can be sure of the quality of the testing carried out.JHH Engineering usually provides comprehensive reports of the testing carried out within 48 hours and covers the whole of the United Kingdom and the Republic of Ireland.