What happens next?

How to clean the exterior of your garage
Use a jet wash machine to clean the walls of the garage.
This will get rid of the build-up of dirt and make the brickwork look fresher. However, don't use the jet wash machine on the garage door or the windows as this may cause damage to these more fragile surfaces.

--Remember that these machines can be extremely powerful, so you might take some of the cement away when cleaning the brickwork. Once the walls have been treated, use a cloth and a bucket of warm soapy water to clean the windows.
--Follow the directions on the product's package or come across it on your floor at a hardware store. Clear up any build up and spread newspaper on the garage door and window frames.
--Now, set the jet wash machine about 1/2 to 1/2/3 an inch from the wall. Take a hose or float and make sure it is clean.
--Sweep the floor and remove any old fecal matter. This is done by applying a free-flowing cleaning solution to the dust and dirt.
Remember that these machines can be extremely powerful, so you might take some of the cement away when cleaning the brickwork. Once the walls have been treated, use a cloth and a bucket of warm soapy water to clean the windows.