Concrete block supporting cottage eroding away.


Old 03-29-11, 11:23 AM
unique3's Avatar
Thread Starter
Join Date: Jan 2004
Location: Winnipeg, MB Canada
Posts: 208
Received 0 Votes on 0 Posts
Concrete block supporting cottage eroding away.

I have a log cabin with a crawl space under it. The perimeter of cabin is a poured concrete footing with the logs directly on top. In the middle of the cabin supporting the log walls there are 4 concrete blocks with a posts that supports the bottom of the walls.
The floor joists are about 9" above the ground level.
5-10 years ago the previous owner dug out trenches under the cabin to allow access to the plumbing, one of these trenches went directly beside a concrete block and over the years the soil under the block has caved into the trench, now the concrete block sides on about a 35-40 degree angle.
I don't want to restore the block to the correct height because since then the seams between the logs have been re grouted and I don't want to crack the grout.

Any suggestions on how to prevent the block from moving even more?
Should I just back fill around the block?
Sponsored Links
Old 03-29-11, 02:18 PM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 47,665
Received 323 Votes on 287 Posts
What I'd do would be to install temporary supports on both sides of the failing pier and then remove those blocks, dig down to undisturbed soil/ground and then pour a footer and replace the blocks. I'd be more concerned with doing this right and not worrying too much about the grout...... even if it meant I had to redo it.
Old 05-13-11, 04:24 AM
cropdiesel's Avatar
Join Date: May 2011
Location: USA
Posts: 1
Received 0 Votes on 0 Posts
marksr's solution is exactly what I have been instructed to do by a professional in a similar situation. I'm a Newbie on this forum, but I & my neighbors have dealt with similar erosion/sinking issues with my log lake house. The simple advice I can share is this: The structural integrity of your cottage is priority to any & everything else. Re-grouting is an easy fix that you can do on your time, sounds like the block pier needs attention before it becomes a bigger problem.
Old 09-22-11, 11:51 AM
unique3's Avatar
Thread Starter
Join Date: Jan 2004
Location: Winnipeg, MB Canada
Posts: 208
Received 0 Votes on 0 Posts
A few weeks ago we placed 2 6 foot metal C shaped beams in the base of the trench with the C down and used a jack to push them into the soil. We then put preformed concrete blocks on top of them, the beams help spread the weight out across 6 feet instead of just a couple where the blocks are. We then jacked up the cottage with the jack on one side of the block and put a new wooded post in on the other side. The original post is carrying no weight but I left in place in case the new one decides to settle.
We were also able to regain about 3/4 to 1 inch of what has sagged over time.
Few weeks later everything still looks good, no settling has occurred.

Oh and no grout cracking, on further inspection is actually a flexible chinking that looks like grout.
Old 10-07-11, 11:51 AM
BridgeMan45's Avatar
Join Date: Oct 2011
Location: USA
Posts: 3,194
Received 1 Vote on 1 Post
Good to hear you were able to stabilize things, but there are a few things to note:

I hope you gave your "metal C shaped beams" a good coat of paint (or used galvanized) before installing them. Otherwise, expect them to corrode out and weaken considerably over time. Unpainted steel is rarely used for shallow foundation work because of this. The steel channel sections you used were also oriented with their weak axis vertical--had you installed them with webs vertical and flanges horizontal, they would be approximately 4 to 6 times stronger in supporting the cabin's vertically-applied loads.

Don't lose sleep over any of the foregoing--it may take many years before any ramifications become evident. What you did is good, but it could have been better. Next time you'll know!
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title: