Mary in PA
During initial discussions with the framer, I asked what things he wanted from us to help him to his job. I try to do this with all of the subs, as it gives them a chance to provide input and educate me about the work flow. The framer requested we backfill before he started work. I readily agreed, even though I didn’t see what the big deal was one way or the other. Now after working on the construction site myself, I completely understand the framer’s POV. Jumping back and forth over the trench and walking on the soft uneven piles of fill is very tiring. I was really looking forward to backfill.
In preparation, John used a marker to write on the inside of the block wall showing the desired finish height of the dirt pad. On the outside of the building, the excavators could use the parge coating as their guide to backfill height. To protect the sill from moisture, we wanted as much as 16 inches above grade rather than the 8 inches called for by code.
The excavator ‘boss’ that I had been dealing with for the previous work was not on site the day they came to backfill. The three-man crew was already working when I arrived and seemed intent on their task so I didn’t interrupt them – and I wasn’t even sure which of these guys was in charge. I walked around a bit checking over things and that’s when I noticed that the pile of good-sized angular rocks that had been sitting on the dirt pad were now laying in the trench – right on top of our 1” water pipe that was about to be backfilled. I had used the rocks to weigh down the plastic tarps while doing the foundation insulation. I didn’t clean them off the pad because we thought that we would just cover them with gravel when we eventually poured the slab. I guess it was nice of the guys to clean them up, but they shouldn’t have put them in a trench where they could create a puncture hazard to our water line! So I got belly down on the dirt pad (the only way I can reach the bottom of the trench) and started picking out these rocks. Two crew guys standing nearby seemed surprised and asked me what I was doing. Over my shoulder I told them I did not want these rocks in the tight trench with the water line. I guess they agreed that probably wasn’t the best thing to do and the older of the two of them ordered the younger guy to help me fish out the rocks. It only took a few minutes to toss the rocks into another section of the trench, so I’m glad I spotted it before they backfilled that area.
Other than the brief interaction regarding the rocks-on-water-pipe problem, I didn’t have any discussion with the crew. I left while they were still working on the inside pad and before they even started the outside of the building. As it turns out, lack of discussion and/or leaving were mistakes on my part. When I returned the next day, I was disappointed to see that the exterior backfill was much too high up on the foundation wall. In some places it was only five inches or so from top of block – way too high. I wasn’t sure how much settling to expect. Maybe it will sink back down, but it is hard to see how it will settle enough to bring the final grade to where we wanted it, about 14 inches below top of block.
Another problem occurred as they backfilled the interior pad around the plumbing pipes. They accidentally rotated the pipes so that the vent and drain pipes were no longer vertical. John surmises that the two 22.5-degree elbows we put in to fix the alignment problem created a broader area than just a straight-pipe run, and when tamped down, it lead to the rotation problem. Fortunately, John was able to correct the problem and get them vertical again. And we’ll pressure-test everything again to ensure that we were still good on all our connections. It is interesting to see how a fix for one thing can lead to a problem for the next thing.
So backfill was a mixed bag in terms of results. While it was good to get it done, I was disappointed that some of it may need to be fixed up to get the results we want. I’m still learning to manage the things that happen on site and how to deal with subs, but learning a lot with every day.
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