Disaster Mansion

Some day we’ll have a nice concrete floor on the basement instead of of a big sand pit, however, before that can go ahead we have to have the plumbing roughed in and fix anything that will be hidden beneath the concrete floor. Once such item is a load bearing pillar support which the builders put in to support our new LVL beam. This carries a lot of weight and not something you want to see fail. As you can see in the first photo, the laser levels shows that the concrete support block has already sank by 1/2″ on the right and to the left you can see that half the support was built over a 2″ polystyrene sheet and the block has already cracked in half.

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I would have liked to have started on this project earlier but we had to wait until the temperatures got consistently to 50°F and above. Winter lasts too long here and we even had snow earlier this month.

To replace the concrete block we needed to install temporary supports to reduce the load on the existing pillar. After talking to our friends and advisors Derrick and John Paul we jacked the beam up on either side with a couple of screw jacks which Derrick kindly lent us. I slowly cranked up the jacks, checking regularly to see whether the load had been taken off the existing pillar until it got to the point that I couldn’t turn the jacks any more and the existing pillar still wasn’t free. Luckily John Paul stopped by and suggested we add an additional two temporary supports. For this I need two more jack screws, I managed to buy one locally on craigslist and the other on ebay. By the way I wouldn’t  recommend hydraulic jacks for this kind of work as they leak down over time.

With the four jacks I eventually managed to free the old pillar and set to work removing the old concrete block with the trusty jack hammer. I made the forms for the new block as an 18″ cube with an ample supply of 1/2 rebar, kindly cut by our resident rebar cutting expert Aimee. We used 5,000 psi pre-mixed mortar (just add water) and got through about seven 80lb bags. My dad used to tell me that when he was young the weight of the bags was double that – glad I didn’t live then as 80lbs is quite heavy enough. We mixed the cement by hand which also gets hard after a time!!! Maybe down the road we’ll buy a cement mixer as it would get plenty of use. The new support is probably at least 4 times larger in volume than the old block and we left it to cure for about 10 days.

I was hoping to re-use the old support but that didn’t work out so I laminated four 10″x2″ planks together and made some nice headers and footers to help spread the weight. The new pillar is probably about 15% beefier than the previous one.

Today I installed the new pillar and released the pressure on the temporary jacks. There was some groaning noises but that’s probably just the wood settling in and I did re-add one of the temporary supports just in case. Tomorrow, I’ll bolt it down to the concrete block.

I’m glad that’s over with as jacking up your house can get a tad stressful! All in all I think this was a good job worth doing, just a shame we had spend our time, energy and money to redoing it. There are also another two supports resting on polystyrene which will need replacing but they can wait.

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Today we removed most of the parge coat from the house and in case you’re wondering why, it was because the existing (modern) parge coat was done with Portland cement over the existing lime mortar walls. This is not a good idea as pointed out in this article:

Lime is the base product widely used to produce mortars, plasters and limewashes for traditional buildings. Lime has distinct advantages over cement based alternatives for external rendering of traditional properties. Lime is less dense and more vapour permeable than cement based materials and does not trap water in the substrate which is the leading cause of decay in all buildings. Lime materials accommodate general movement better than harder cement based alternatives and are closer in strength to many of the types of stone and brick used in traditional construction and therefore do not exacerbate their deterioration.

Instead of using lime materials, many traditional buildings are repaired and renovated using harder, impermeable materials designed for modern buildings which use completely different construction methods. The result is often worsened damp problems. The simple advantage of using a lime render is that it allows the walls to diffuse any water vapour that penetrates into them, referred to as the free passage of moisture vapour.

which to summarize means that a Portland parge over a lime mortar wall will trap moisture in your house, cause your walls to deteriorate and will likely crack due to its inflexible nature. By the way that is snow in the video.

To remove the existing parge coat I used our recently purchased rotary hammer drill. What a great tool.

By the way, where the mains water pipe goes into the house (clad in blue foam insulation) there used to be a door and steps down to it. It probably got filled in when the garage and driveway were built.

In the process of preparing for french drains and new footings we’ve already cleared a trench around most of the house so this is an ideal time to do a fresh parge coat as well as to repoint all the corners etc. We’re hoping that our friend Derrick can do the work as he is an expert in old school plastering. Once the parge coat is on it’s recommended we wait for two weeks for the parge to partially cure before we apply a lime wash which is an old fashioned whitewash, the sort that you’d see on old farm buildings. Allowing another two weeks for curing we can start to install our french drains and fill the trench in. It will be nice to have our paths around the house back as currently you can’t walk around the house.

Concerning the the new parge coat I’ve been talking to Chris at LimeWorks and he suggested a 3.5 Natural Hydraulic Lime for the parge and a 5.0 Natural Hydraulic Lime for any small structural repairs. I can highly recommend Lime Works if you have lime mortar in your old house.

Aimee in the meantime has been double bagging asbestos tiles which were removed from a section of the house last year. This is the second load we’ve disposed of and it will be good to get rid of the stuff. We have to make an appointment at the dump before we take it in and were told that it ends up near Syracuse which is about 200 miles away.

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