How do I waterproof/seal my front porch?

by Jay6409855

The wood that was used is NOT treated lumber! The porch is over my concrete basement. I need to stop the rain/snow from coming thru the tongue and groove and into my basement. I also need to know what type of fiberglass insulation I need to use to help keep the cold and heat from coming in? Unfortunately this contractor did a very shotty job TWICE, using untreated lumber.. I'm stuck with it. I was thinking a thick paint may work? I will also be caulking around the perimeter of the porch that butts up to the house, as the water comes in there as well. What a mess, right?!

  6 answers
  • Kmdreamer Kmdreamer on Jul 26, 2018

    You would have to put another floor over that

  • Karen Pullen Karen Pullen on Jul 26, 2018

    Use a exterior grade penetrating wood stain. Timber oil seems to be a common part of the name of many of these products.

  • Jcraw Jcraw on Jul 26, 2018

    This is not nesessarily the solution to your problem, but good advice and perspective. Because a heavy coat of paint will not solve your dilemma.

    Please note that they suggest sealing the basement as well.

    Perhaps you ought to look into Marine paint/sealant. Ascertain what wood your bad-faith pro used. It could make a great difference in the sealant/paint used.

    Lots of informed folk here willing to help.

  • Oh my goodness! What a nightmare. When all else fails, call your local permit department and request an inspection as obviously your contractor failed to pull the proper permits. They will tell you exactly what is required to remedy. Then, if need be, hire a licensed contractor to perform the work for you if the repairs are beyond your skills. Here is how to hire a contractor.

  • Sharon Sharon on Jul 26, 2018

    What do you mean over the basement? do you mean it butts up to the foundation wall and its leaking now? First I would take a level and see if its tilted up against the house wall, or if its level, or if he's sloped it out towards the yard. Porch decks are not made to be waterproof as water on them will cause them to rot faster. Is there a flashing at the porch deck and siding?

    Does ths guy have a contractor's license? if so I would get on your States' Contractors Licensing Board and file a complaint.

    Does this porch have a roof? how is the water getting onto the porch? are the gutters in good repair and moving the water out to the corner's of the building? Does the edge of the roof extend beyond the porch deck about a foot in 3 sides?Every year I have someone tap the gutter cross posts into the wall as gutters begin to sag away from the facia, and then I have them run a bead of silicon caulk along the house and the top edge of the gutter to prevent water running down the soffits. Have you checked the roof is sealed well where it butts up to the house roof?

    If you paint it, I would go with Porch & Floor Paint, and you don't want it too thick as it will just peel off. Personally, I like a good deck oil stain for raw wood - it will never peel and you can just give it another coat in a year or two.

    As to waterproofing your basement, if you can get under there, I would add a rubber waterproofing to the foundation wall. And use Quikcrete caulking if there are any cracks or void. And you could dig a french drain under there to move the water away. If the gutters end right on the deck edge, add some extensions out into the yard to move the water away from the foundation - even just adding an additional elbow with a long piece stops water pooling along foundation.

    As to cold air coming in, I would insulate the rim joists and the floor plate.... You could also use 1"-1 1/2" rigid foam insulation and spray foam to insulate it also....

    • See 1 previous
    • Sharon Sharon on Jul 26, 2018

      Then I would caulk the edge along the house deck and add a metal L-flashing to prevent it running down the foundation wall. If you can access it from the basement window, I would add some rubberized foundation coating to the foundation wall. And I would check the glazing and caulk around the window to make sure thats not the water entry point.

      If you have a rainy season/winter, you could add foam insulated panels under the 3 sides of the deck to keep it from coming in under the porch,,,, that 1"-1 1/2" 4'x8" foarm insulation panels won't cost more than $20 at home depot/lowes. Tape the seams, and use firring wood strips to hold in place.

      But do check that roof line next time it rains to see if it needs sealing with some caulk.

  • Sharon Sharon on Jul 26, 2018

    Oh forgot, you can buy a waterproofing spray from Rustoleum called NeverWet. Its a 2 part spray. I just scored it at the Dollar Tree for $1.