Plastic, copper, etc., tubing inserted into a run of existing pipe, thereby eliminating the need for a new trench.
                                                            
                                                     
                        
                                                
                        
                        
                            The insulation material, usually of higher compressive strength, joined to the existing insulation in order provide reinforcement to a pipe support.
                                                            
                                                     
                        
                                                
                        
                        
                            Heating units that retrofit into an existing fireplace (masonry or factory-built). They burn wood, gas or pellets and offer superior efficiency.