On Monday, we will have selected portions of the River House sprayed with closed-cell foam, the insulation product we will be using throughout. The areas that will be addressed are ones that will become impossible to reach later as more and more of the mechanical infrastructure is put in place (ducts, pipes, vents). Two such vents which I added to the house today are for the ERV (Energy Recovery Ventilator) which is a critical component of a tightly sealed house. It is responsible for continuously bringing fresh air in to replace an equal amount of stale air. The intake and exhaust vents each require a 10-inch pipe placed through the siding of the house. The pipes need to be installed with an exact amount of protrusion from the siding to facilitate the later installation of a vent cap. This is the sort of task that is very difficult to do precisely when working alone but led me to a very clever idea for simplifying the task. I measured and marked the distance from the back face of the sheathing to the end of the tube. I then installed four pop-rivets and left their tails in tact. This gave me four bearing points to register the depth of the tube in the siding while I anchored it in place with screws.