Historic Renovations, Part 3

Prior to launching into a full scale renovation or restoration of your school building you should evaluate the condition of the building. A full structural review should be performed by a licensed engineer to determine if the building has any deficiencies that should be addressed. You might notice that a floor is sloping or has soft spots when you walk over a certain area. This may be the result of the foundation moving, termite damage, or the result of water damage. Wood roof trusses have a tendency to sag over time, if your roof has a low slope or is flat (which was common construction practices in the early 1900's), the roof could be ponding water. Over time as the roof continues to sag as the ponding becomes more pronounced, the roof structure could collapse under the weight of the water. I have seen this condition occur,  thankfully the roof did not collapse while school was in session, it occurred over a weekend.

The walls should be examined as well. The majority of the older buildings were constructed using the walls as 'load bearing'. This means the walls directly support the roof structure. Often times the walls can shift due to foundations moving. If the walls are leaning out of plane, this is a dangerous situation and must be corrected. Typically the exterior walls are load bearing as well as each side of the corridors. Caution must be taken when opening or cutting into these walls are desired to expand rooms or reconfigure spaces. Small openings for standard doors is usually not difficult to accomplish, each opening will require the head, or top of the opening, to be structurally reinforced.

All systems in the building should be evaluated including the electrical, mechanical, plumbing, roofing, and building envelope (walls, windows, etc). The cost of repairing/replacing these systems have a major impact on the project cost and should be carefully evaluated. A general rule of thumb is that if the cost of renovating exceeds 50% of the cost of a new building, you should consider building new. This of course does not take into account the historical value of the building to the community. This could far out weigh the cost implications.

Michael D. King AIA