Exterior French Drains
An exterior French drain consists of excavating a ditch along the foundation. It is dug below the footer and graded to the surface. In order to install an outside French drain, all cement porches, patios, sidewalks, shrubs, or any other obstacle along the foundation need to be removed. Unfortunately, there is an added expense for this work, therefore, most people choose inside French drains. However, if an outside French drain is preferred, sealing the outside of the foundation prevents any water from entering the block, thus, keeping the inside walls dry.
An exterior French drain is an extensive process. First, you remove any shrubs, porches, or obstacles in the way. Secondly, excavation along the foundation to below the footer is done with approximately 90% of the dirt being hauled away. Also, it is crucial that the French drain pipe is below the bottom of the footer to start out grade. The pipe must grade down hill. D-Bug Waterproofing is very particular on grading. By using a level, we accurately ensure the pipe is perfectly even. (We don’t warranty our work because we want to redo the job, we warranty our work because we do it right the first time.)
After the ditch is graded, the wall is cleaned with scrapers and wire brushes. The wall is then tarred with roof cement or flashing cement. When the tar is dry, a 3 foot high piece of rubber roofing is placed along the bottom of the wall and draped over the footer. Next, 3/4 inch pink board is attached to the foundation wall to grade level, followed by the joints and the top of the pink board being sealed with roof cement and muslin or fabric. The ditch is then lined with fabric to keep the gravel and dirt separated. Gravel is then placed on top of the fabric filling the ditch to grade level. As well, the gravel is also covered with another layer of fabric. Of course, 6 to 12 inches of dirt is put back against the house (depending on what gets replaced along the house). Whether it’s shrubs needing planted or pouring new cement patios; D-Bug Waterproofing replaces or does whatever is needed to get the house looking as good as… or better than… before we started. Finally, we regrade any areas of the yard that may be in need (including adding new top soil if needed), and lastly, planting grass in all areas of excavation.