Posts Tagged ‘masonry’

Window sill replacement

Friday, August 27th, 2010
Written by Marcus de la fleur

The beauty of remodeling is that you think you are done with one job, only to find out that you are not.

I proclaimed that we had taken care of the basic masonry repair in the basement and around the windows. That was before I took a close look at the window sills of the two basement bathroom windows.

The sills, once one nice piece of carved limestone, were pointing and sloping in all sorts of directions, and were a lit wobbly and cracked into three pieces. A situation that was incompatible with the installation of new windows.

I still had salvaged limestone sills in the yard from a nearby tear-down that I could use for the replacement. First, though, I had to remove a lot of concrete that was poured all along the western edge of the house, presumably to keep water away from the foundation wall.


Removing the old sill pieces was comparatively easy. I also removed some of the loose limestone from the foundation wall under the sills and mortared them back into place. This should provide the sills with a firm footing. Last but not least, I fitted and placed the new sills, making sure that they were level across the window, but had a slight slope outward into the yard.

Does that conclude the masonry repairs? I am afraid not. The list of minor and major masonry repair works is still growing.

The old window bars, which are let into the masonry wall, have rusted so much that they have begun to push the brick work out. We would like to install new bars and at that time repair the brick around the outside window opening.

We also have the issue with the cement parging around the bottom of the house. The parging covered up water-damaged brick, which actually made the problem even worse because it prevents the masonry from drying out. We would like to remove the parging  and replace all the water-damaged brick.

Then there is the foundation wall that we will need to re-point once we start excavating for the footing drain and insulation. Cathy and I know that we will not shoulder that task again but will have a pro on the job.

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Basement re-pointing

Sunday, August 8th, 2010
Written by Marcus de la fleur

Late last year I re-pointed (or tuck pointed) some areas of the interior brick wall on the first floor. It was only necessary where I had localized moisture damage.

I am now moving down one floor, into the basement, where the moisture damage is much more wide spread, and as such a lot more re-pointing is needed. There are two general kinds and causes of moisture damage.

The soaked wall

A part of the front basement wall was completely soaked. The source for all the moisture was a disintegrated roof drain that must have had water running down the brick work for years.

Having had the wall open and exposed for a few months now allowed some of the moisture to dry out. Still, we will need to re-point this entire wall section.


Sorry – no images of raking out the joints with the angel grinder. Too much dust for the camera to handle.

Parging trap

The rest of the re-pointing work was limited to the lower section of the brick work in the basement. Above that, the mortar is in pretty good shape.

The line between deteriorated joints and sound mortar coincides with the cement parging on the outside of the building.

parging-01

The parging acts like a vapor barrier or vapor retarder and only allows the brick work to dry out towards the inside of the building. This one directional drying process is not very effective and will cause elevated moisture levels in the masonry. That in turn led to the deteriorated mortar joints on the inside.


Re-pointing these lower sections of the brick work around the basement is only half the remedy needed. To fix the elevated moisture levels, we will need to let the wall dry out into both directions – we will need to remove the cement parging on the outside wall.

Why is the parging there in the first place? Well, it is one of those ‘sweeping it under the carpet’ issues. Rather than fixing a problem, it gets covered up.

The problem here was water damaged brick above the limestone foundation.

parging-02

The solution was and is to replace the brick, keep moisture away from the wall, and let it dry out in both directions.

Hmm, sounds like another interesting masonry repair project, doesn’t it?

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L’arc de triumph

Saturday, July 31st, 2010
Written by Marcus de la fleur

Repairing the masonry work on the inside around the hole in the wall – namely the one added basement window – is less than half the story. Dealing with the exterior repairs is much more interesting.

All original windows have proper stone window sills. This one had not. It was half-heartedly set on the limestone foundation wall with plenty of nooks and crevices for critters, water and air to get in and out.

I fixed that by removing some of the limestone to make room for a salvaged cut stone sill.

Then, as with the inside, I deconstructed the edges around the window back to the original brick work and rebuilt it from there with salvaged brick and the right type of mortar.


The work around this added window was bad, but at least it was consistently bad.

The window had no header on the inside, nor on the outside. Adding the outside header was a little involved.

We took our cues from the architecture around the original windows, which all have a two layered segmental brick arc. This construction is structurally super sound, and something that has been used for centuries. Just think of arched cathedral ceilings.

To install my modest arc header, I build a template that I fitted into the window opening. It allowed me to mortar in place the two segmental brick arches. Once the mortar was cured – a couple of days later – the template could go.

From the removal of the original windows to the small masonry repairs at every window, this was a bigger task and accomplishment, which we began to refer to as our little l’arc de triumph.

I like to think that its sustainable impact could also be somewhat triumphant. So many thinks that are done or that we do around our buildings are often executed with so little thought, which can lead to long term damage rather than adding to the longevity of a structure. It is about the other side of green.

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Fixing a hole in the wall

Monday, July 26th, 2010
Written by Marcus de la fleur

I removed the old basement windows and now have repair work in the masonry opening ahead of me. There is some moisture damage to take care of as well as filling the recesses of the old wooden window sill and head in the top and bottom corners.

One of the windows is an unusual case and requires a little more tender-loving care.

We discovered during our basement deconstruction that it is not an original window, but had been added sometime later.

bsmt-win-04

This is a curse as well as a blessing as with most other things that had been added later in this building. We don’t mind having the extra window in the basement, but we now have to deal with shoddy masonry work around the edges, which was done with the wrong mortar. But worst of all, this window had no header and thus no support for the two floor joists. Instead, they were just resting on the window jambs – not something you can call a structurally sound solution.

That said, this setup obviously has worked for a number of years. Nevertheless, I got increasingly nervous each time I looked at the window and decided quickly to shore up the non-supported floor joists.
I now could safely remove the shoddy masonry work around the window edge, deconstructing everything back to the original brick work.


After everything was cleaned out, I began to rebuild the masonry opening with salvaged common brick and the right mortar (type O). I finished the job by crowning the window with a 4 by 6 old growth header, the same kind of header we have over all other basement windows. This set-up has a 100+ year successful track record … enough to convince us that this is the way to put it back together.

This takes care of the inside work. Next step is to get the outside part of the window fixed.

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Painfully slow

Tuesday, July 6th, 2010
Written by Marcus de la fleur

Sounds real positive, doesn’t it? Well, after my little rant about the other side of green, I though it is appropriate to follow up with our re-pointing progress on the foundation wall – which is painfully slow. But so was the process of raking out the joints, which preceded the re-pointing.

Originally, I was all excited about restoring the foundation wall to its original beauty and having it exposed to the interior living space. Little did I know then about the time involved for the tasks at hand.

Before we began the re-pointing process I washed any remaining mortar residue and dust out of the joints. I also had to determine what type of mortar to use. Martin Bazula, a restoration mason, suggested that the original mortar was type O.

The replacement material (mortar for the re-pointing) should match the original material (mortar) as close as possible. So, type O mortar was what we mixed and used.


Because most of the joints were several inches deep, we had to re-point in several stages. On the first pass, we filled the joints half way and let the mortar set for a day or two. On the second pass, we finished filling the joints.

We again let the mortar set for a day or two before we added the finishing touch, which was brushing any excess mortar from the lime stone with a wire brush.

It was slow, but we are very happy about the end product, in particular if we consider where we started.

foundation-wall-01 foundation-wall-02

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Pouring the basement floor

Monday, June 14th, 2010
Written by Marcus de la fleur

We are getting our new concrete floor! This is our big day after months of preparation and research.

The research was not only about the technical aspects of moisture management and how best to insulate, it also involved logistical questions, i.e. how do we get 21 cubic yards of concrete down into the basement.

There is really no good way to get the concrete directly from the truck to where we need it. We could get the chute of the truck to the very back of the basement, but how would we get all that concrete to the front?

Using wheelbarrows, such as for the spread footings, is not an option unless I am willing to spend several days on the pour. I was thinking of using 20 foot long portable conveyor belts. But how would I maneuver them in and out of the basement?

Pumping the concrete is my best option, as I had been told a number of times, and slowly came to accept. I could not find an equipment rental place that had small, trailer mounted pumps, but found a company with a small truck mounted pump that came with an operator.

concrete-pump-01

We can’t just pour any type of concrete into the pump, but need what is called a ‘pump mix’. It means that the concrete comes without air (concrete is often air entrained) and is a little lower on the stone content.

concrete-pump-02

I ordered and scheduled the pump mix a couple of days in advance. We set up the pump, the concrete arrived right on time and we were ready to go.


Oh boy, time can fly! We had three truck deliveries, spaced 20 minutes apart. We pumped and poured like there was no tomorrow. While pouring, we spread the concrete to a rough elevation.

When a large enough section was filled, Neil and Greg, the finishers, screened the fresh concrete to the finished elevation. Sort of like I screened the gravel base, but this was going much faster!

Once done, we took a little break to let the concrete set. Not for too long, because Neil had to go back to the front and start with the expansion joints while the concrete was still fresh enough.

expansion-joint-01

While Neil was taking care of the joints, Greg fired up the troweling machine to add the finishing touches to the floor, except for odd corners, which required hand troweling.

It was a long day, be we are sure glad to have this milestone behind us!

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Taping the insulation

Monday, June 7th, 2010
Written by Marcus de la fleur

Let me squeeze in a quick note on insulation and air movement, something that is not much talked about.

Imaging you are skiing in the Rockies on a bitterly cold and blustery day. No problem, because you have a very cozy skiing suit. What if the skiing suit has a couple of thin vertical slits on the front and the back? Now you are freezing your behind off, because of the cold air infiltration on the front and air exiting on the back.

Although many would classify the ski suit example as common sense, we don’t make the connection to our homes and insulation.

An exterior stud frame wall with batt insulation is an exact analogy to the ski suit with slits. There is plenty of air infiltration potential between the batts and studs, unless the exterior wall has an air barrier.

See also: Thermal control in buildings (buildingscience.com)

The listed R-value of insulation does not take into account air infiltration, which can severely compromise its effectiveness. The bottom line is that any insulation is only as good as it is airtight.

This principle really stuck with me and it didn’t take much convincing that I probably should think about the air tightness of the basement floor insulation.

Solution: Taping all the seams of the foam boards.

insulation-taping

That sounds easy, except that I had a tough time finding the right tape. Don’t use the pervasive duct tape! You need sheathing tape, which appears to be much less common. I finally found it tucked away in far corner at one of the typical home improvement stores.

Here are two product examples of sheathing tape you find on the web:

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A bump in my task list

Thursday, May 27th, 2010
Written by Marcus de la fleur

Actually, it is probably more accurate to talk about the rocks that I threw into my own path – lime stone rocks that is.

Funny how task lists and schedules rarely ever work exactly as planned. I had my step by step task list for the basement floor installation thought out, but now begin to add line items.

I have put the finishing touches to the aggregate base with the recycled concrete and I am ready to install the insulation. But wait; there is still a lot of stuff in the way.

lime-win-01

I am looking at piles of limestone that I have stored on the new spread footings. Those lime stones were loose pieces from under the windows that I need to mortar back into place. I carefully removed them and stacked them the way they had to go back into place.

lime-win-02

That limestone has to go before I can start with the insulation installation. Should I move the limestone and store them temporarily somewhere else? I don’t think so. That would be like messing up a Rubik’s cube, or trying to put a complex puzzle back together.

I will be much better off fixing the foundation wall under the windows now, mortaring the lime stone back into place.

lime-win-03

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Wall washing

Thursday, May 13th, 2010
Written by Marcus de la fleur

Thank God I am done raking out all the joints on the limestone foundation wall. But there is a whole lot of small residue and dust left. That all has to go before I can repoint to assure that I get a good bond between the lime based mortar and the limestone.

I started with the shop vacuum but only got some of the finer and dryer residue out. To remove the rest, I will need to spray out the joints and wash down the foundation wall.


This is a good time to do this. I can let the water with the residue run down onto the clay were it soaks into the ground. It did not take that much water and the residue can stay behind and will be covered by the aggregate base for the new floor slab.

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Raking, and no end in sight

Tuesday, April 27th, 2010
Written by Marcus de la fleur

No, not in the yard but in the basement – on the foundation walls.

Because the landscape around the house does not drain away from the building everywhere, the foundation wall had wet spots. The previous owner “solved” the problem by covering the limestone rubble foundation with cement parging, effectively trapping the moisture in the wall.

Trapping moisture in a masonry wall is always a very bad idea. Our plan is to solve the drainage problem around the house, insulate and waterproof the foundation wall from the outside, but let it breathe and dry out to the inside.

Great, except we first have to remove the parging, which was for most part a pretty painful job.

parging-removal-01 parging-removal-02

I am eternally grateful to Cathy and many of our friends who chipped away for days, until all parging was gone.

Are you hoping it goes uphill from here? Not yet, because next I have to rake out the old foundation joints so that I can repoint them. This is almost as painful as the parging job (forgive the upbeat description).


I began with the grinder, removing any cement residue and sections of hard mortar. After that I raked out all loose mortar to a depth of two to three inches at times. Last but not least I will need to wash out the joints before I’ll be ready for repointing.

I did not realize how long our foundation wall is, until I started this job! The really scary thing is that I may have to do the same job again on the outside of the foundation wall.

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