There’s an unfortunate misconception out there about ground cloths – namely that they are the proper application for preventing erosion under cedar decking. Lake Oswego and Portland residents can find plenty of misinformation about ground cloths and under-deck drainage; even a cursory Google search turns up a plethora of web sites encouraging homeowners to install ground cloth underneath their decks. We’re not sure how the idea of using a ground cloth to prevent erosion first came about, but we can tell you why this approach is foolish.
Proper drainage. First, ground cloth actually makes it harder for under-deck moisture to drain away. As evidence, consider that this kind of fabric is often used to prevent weed growth. Landscapers often install ground cloth around their prized specimens to create an impenetrable layer through which plants cannot grow. (In turn, this means that the landscaper has less maintenance work on his or her hands.) Just as ground cloth prevents weed growth, it also prevents quick drainage. In areas like the Pacific Northwest, where rain is common, this can be a real problem.
Evaporation. Second, as moisture pools on top of ground cloth, it has no way to escape save evaporation. If you have a ground cloth under your cedar decking, Lake Oswego residents, you may have noticed a tendency for the deck to become unbearably humid and hot. If sunshine follows rain (as it so often does in this corner of the country), pooled water on ground cloths evaporates, creating a miserable microclimate in exactly the wrong place – on top of your deck, which should be the best place to relax and enjoy the weather. Worst of all, this evaporation cycle is hard on your cedar decking. Lake Oswego homeowners who insist on ground cloth will find their decking rotting at an increased rate.
For these reasons, we discourage our customers from installing ground cloth. Rather, we recommend decking systems with built-in drainage (such as our exclusive Gorilla Decking). If you love your cedar decking, Lake Oswego residents, but you hate the drainage issues beneath it, we suggest adding a patio cover, which will naturally send water away from your decking area. French drains, water-loving plant species and rain gardens can also help reduce under-deck draining problems.