Your home or property was not built to withstand the forces of high-pressure water ranging from 1,500 ~ 4,000 psi being spayed towards it at point blank range.
This is especially important when it comes to assaulting an irreplaceable historic home or building with typical pressure washing techniques.
Most historic homes have painted clapboard siding that when washed with high pressure, can damage the paint, damage the siding itself, or water can be sprayed under the laps causing moisture damage inside the home’s walls.
Also, a lot of historic homes are built with ornate, one of a kind moldings and trim that give them their character and charm. While their grace and architectural beauty cannot be overstated, the technology of the day fell a little short on window and door seals that would let the cold drafty air pass through. So if air can get past windows, another reason high pressure should never be used to clean a historic home or building.
While most homes were built with clapboard siding, some special homes and a lot of historic buildings were constructed with materials such as marble or limestone.
You may think these two stone materials are hard, but they were chosen as building materials even in ancient days because they were long lasting, yet soft enough to easily be cut into shapes and building blocks.
Cleaning historic buildings with a pressure washing machine that can readily be purchased at Wal-Mart or any Big Box Store can do unthinkable damage to structures that were meant to last for centuries.