04-08-2011 03:53 PM
I need to repair a house wall that is cinder block. The repairs are outside. The cement between several of the blocks is coming out/disintegrating and has caused leaks into the inside. I need suggestions on the best way to remove the cement and replace it to fix the problem.
Also, I need suggestions on how to seal my windows as I they too are leaking (both from the top and the bottom).
04-09-2011 02:26 PM
Thanks for your question and welcome to the community!
Sorry to hear about your block wall failure
Let's get you on the right track to get the solution you need for your wall.
If you have easy access to the wall on the outside, first look at the problem areas that you know are leaking.
The areas that you see that are badly damaged or missing mortar will need to be taken off so as to put the new cement down.
To get the old or loose mortar/cement off I would recommend using 1 or both of the following tools shown in the pictures below. These are the hand-held, won't cost you a lot, and work great for getting in between those cracks to get the bad mortar out. Remember ONLY do the bad mortar, if you see other mortar in good shape, then leave them be. If you have a large area of mortar to contend with, we do sell wire brush or grinder attachments to your drill to save time.
Once you get the old mortar off, I would recommend next to apply a Hydraulic water-stop cement. We sell them in our paint and building materials department. The one that my customers ask for more is shown in the picture below, you can use either one for this product. It works great for stopping moisture and fixing small holes in your exterior block wall.
Apply the cement with a patching or brick trowel to ensure the gap gets completely covered. This part requires some extra equipment for you, such as gloves and appropriate safety gear you may need. Here's a diagram of this in action:
Now that you have your gap covered, consider using a Hydraulic cement based paint on the inside of the wall to further prevent moisture leaks coming inside.
One of our paint experts on the community, PatInPaint, has done a more in-depth video post regarding your block wall question, his video and post can be found here.
Now as for your second question regarding sealing your windows...
Check your windows on the outside to ascertain how big of a gap that is allowing water inside your walls. Make sure too that the leaks are not damaging any drywall or wood frames on the inside near your window and sill.
After doing that, I recommend using a form of backer rod and sealant caulk IF the gap is 1/2" or wider. The backer rod works great for filling in the gap while the additional layer of caulk will protect the window and frame from the elements. To fill it in, the backer rod acts as foam that you can insall in the gaps either with your hand or screwdriver tool to make sure it is inside the gap. If you have a smaller gap, then you can use simply the caulk. One brand of sealant caulk I like to use is anything that is silicone based or 100% silicone. They are weatherproof, easy to work with, and they will not break down over time like some acrylic based caulks. I have included a picture of the backer rod as well as one of the caulks to use:
Well kittyfiend, please let us know if this helps you out, and if you have any further questions, please do not hesitate to ask,
I am a 12 year Home Depot Store Associate, trained and authorized to help people on the Internet.