Structural Wall Surgery

While the extending the floor, I was somewhat simultaneously re-framing the only remaining Victorian-era structural wall left in our flat so as to accommodate an opening for the new bedroom door. This door location is only possible because of the floor extension - the new door is squeezed in between the top of the old staircase, the kitchen and the beginning of the new staircase that goes up to the loft.

Perspective from 3D computer model used in the design phase - the new bedroom door and new staircase (upto new loft) meet at this critical location adjacent to the new kitchen

This arrangement was developed in the design phase when it became apparent that in order to open-up the space, yet maximize the size of the kitchen and bathroom, we would have a very tight convergence at this very location. This convergence makes the floor extension and relocation of the door critical to the new layout. At the time it was not obvious this wall was structural (it supports a post that helps hold part of the roof) but having worked previously on this wall, and reviewing the proposed work with building control, I felt confident moving forward.

March 27th - The original Victorian-era structural wall (plaster was removed during demolition)

The "surgery" involved cutting through the existing studs to create an opening that will fit the future door. As in all structural work of this kind, the most important thing is to brace the areas of the wall that are doing the structural work so that the wall does not "know" that you're re-arranging it - it's almost like a magic trick. If the structure realizes what you're doing...you're in trouble...

So the first step is to brace the beam at the top of the wall (known as a wall plate) that is actually carrying the weight of the roof post above it (that helps support the roof). The brace is rather simple - a heavy stud (old growth wood from the original roof) that sits on top of temporary beams that span the opening in the floor for the stair.

The temporary brace to support the wall-plate while structural work occurs

Once the brace was in place, I began to cut away at the studs and re-frame the wall to accommodate the opening. Because this wall is one of the bedroom walls, I did this work keeping the plywood sheathing in place, since the plywood acts as the temporary walls to the bedroom, keeping the dust out. But this made the work more difficult, so I had to go "old-school" and use a handsaw...

Cutting and removing the first pieces of the wall

Using a handsaw at a tight spot where power tools would not fit

The opening is done and new side studs repositioned...all that's left is horizontal member at the top of the door opening

Once all the members that were in the way were removed, I was able to reposition the vertical studs (doubling them up on one side for more strength) and then finally add a double "header" at the top of the door opening. A header is the horizontal member at the top of a door - because this wall happens to be structural, this header is structural and will do the primary work of transferring the weight, or "load", of the roof post to the rest of the wall.That's why the header is doubled up and additional vertical members are added using steel clips to ensure their position and strength.

Once everything was in place, I held my breath and removed the temporary brace...all is good!

The brace is removed and the newly re-framed door opening is complete

Before & After montage. On the left (before): the structural wall and floor - On the right (after): the extended floor with the new door opening

Loft Framing (Part 2)

In anticipation of moving-in tomorrow, we're trying to finish framing the loft floor so we'll have a ceiling above the temporary bedroom. Because of everything that's going on (patching brickwork and  waterproofing the roof ) we were only able to start this work in the early evening, which mean that we had to rush before it got too late.

Jan 25th - the partially framed loft and original structural stud wall

To complete framing the loft, we have to add new joists that are perpendicular to the original loft joists we set last month - these new joists have to change directions in order to accommodate an opening in the floor for a staircase that will eventually come up-to the loft. 

To accommodate this change in direction, these new joists will hang off of a double beam (on one end) and will sit on a structural stud wall at the other end.  Before setting these new joists, the top of the structural wall has to be shortened to the correct height, and a new wall plate (horizontal member) has to be set. This wall plate is what the new joists will sit on.

Trimming the top of the structural wall

Once the new wall plate was set, we also set a new full length beam that will act as the edge of the loft/floor. After this beam was in place, we were finally able to hang the smaller floor joists  using steel brackets.

Setting the first few floor joists on the structural wall

The next morning - a partially framed floor

Adding the remaining joists

By the end of the day we were  able to start fixing the plywood sub-floor...proving a ceiling to the temporary bedroom. While we were not able to completely finish the plywood sub-floor, it will be enough to get-by...at least for now....

Checking everything is lined-up before starting the plywood sub-floor

Fixing the plywood sub-floor to the joists

Roof Construction: Open Heart Surgery - Day 4

If all goes well this will be the last day of our open heart surgery on the roof. It better be - I have a flight at 8:10pm back to NYC - but if there's a major problem I can't leave with the roof half open.

Because we ran into trouble last night aligning the rafters on the side roof slope, we have to start the day with re-aligning them. The plan is to use a string line and a long, straight 2x4 to make sure they are properly aligned (wish we had done that last night!). Once that's done, our day laborers will start installing planks while Jimmy and I move onto attaching the rafters (hopefully straight) on the front roof slope. If all goes well we will have all the rafters re-attached and aligned and all the planks installed before i leave for the airport...

Re-aligning the rafters on the side roof slope

Rafters attached to the steel reinforced hip beam

Starting to attach the wood planks on the side roof slope

Montage of open roof from the living room

Re-fastening the first few rafters on the front roof slope

New planks on the side roof slope (left) - re-attached rafters on the front roof slope (right)

Loose rafters on the front roof slope

Rafter ends - they hook over a 3"x3" horizontal wood stud called a wall plate

Planks halfway up the side roof slope

Attaching the final rafters

Rafters finished - planks almost done on one side...

I had to run to the airport without getting exactly to the point that i wanted - but we were close enough that it was OK. The rafters are completely finished, and the guys were finishing the planks on the side roof slope as I was leaving. They will continue with the planking tomorrow and Friday until it's done - everything will then have to wait a few weeks until I get back from NYC...

Roof Construction: Open Heart Surgery - Day 3

The roof is still half open to the elements so today we're hoping to finish the steel installation and start closing the roof up.

The first step is to install the final piece of steel at the hip rafter and splice it to the lower one. Once that's in, we're going to insert stained pieces of wood into the steel channel so we can easily fasten the rafters, rather than having to deal with steel. It's much easier and faster to screw wood together than having to deal with steel (am a bit fed-up with steel at this point). The other advantage of the stained wood infill, is that it will present a more finished look. Once we wood is in, we'll start setting the rafters back and if we're lucky we can start installing planks.

The morning - steel on one side of the hip rafter, but not the other.

Cutting the ends of the final piece

Bolting the last pieces of steel together

The last splice

The steel reinforcement completed

Installing the wood infill

First piece of stained wood installed

Installing the last piece of wood infill.

Setting the rafters

We ran into some trouble installing the rafters. While we were setting them, I had a sinking feeling that something was wrong...sure enough I soon realized that the rafters were not being installed in a straight line. That may sound easy --if you're just sitting behind a desk--but in reality the slightest difference will create a wavy surface for the planks and slates...definitely a problem. I again realized that I needed to use my knowledge of geometry (and desire for precision) to correct the problem.

Tomorrow we're going to have to unscrew most of the rafters and reset them using a string line and a long, flat piece of wood to double check we were getting a flat surface. The guys ended up getting annoyed at me when i made them stop to figure this out as it was dark and late, but unfortunately this is absolutely necessary.

The wavy rafter

Roof Construction: Open Heart Surgery - Day 2

Today we continued with our open heart surgery on the roof. It's Saturday so we are required to stop at 2pm today...a lot to do with limited time...

Yesterday we opened up the lower portion of the roof's corner and installed the bottom two steel channels. Today, we're opening up the rest of the roof which means that 1/2 of the entire roof will be open to the sky. These next few days will be the greatest exposure of the flat to the elements. Once the roof is open, we'll have to measure the remaining lengths for the top two steel pieces, cut the steel and install them to reinforce the hip rafter and splice them together.

This sounds much easier than it is--for starters we have only one shot to get the correct cuts in the steel and cannot make any mistakes. So we ended up cutting small bits a time to get the correct angles and geometry. We ended up going back and forth half a dozen times before it finally fit, but at least we got it. Because it took so much time to cut the one piece, we'll have to cut and install the final piece of steel on Monday.

Interior view in the morning

The upper half of the roof slates removed - you can now see through the roof!

The ends of the lower two pieces of steel

Interior montage - half of the roof open

Cutting ends of one of the upper steel pieces (this happened 6 times)

Finished end

Bringing the steel onto the bridge (this also happened 6 times)

Lifting it into place (this also happened 6 times)

Once the steel is correctly in place, tightening the splice (connection)

Fastening bolts at the splice

Looking out from the open roof

2pm - covered-up and finished for the day

Roof Construction: Open Heart Surgery - Day 1

Today begins the most intense and dangerous phase of the entire project...and of course the weather is terrible. Fortunately I knew it would rain (because I've been looking at the weather forecast obsessively) and built a temporary roof over us.

Our temporary roof

Today we're doing the equivalent of open heart surgery: we're ripping open 1/2 of the entire roof at the corner; cutting out the structural support of the hip rafter (corner roof beam); removing all the rafters attached to the hip rafter; and inserting a new steel channel on each side.

These channels are around 4 meters (12ft) long and are probably the heaviest items we've had to deal with so far. Because things have been going well with Jimmy and our two Romanian day laborers, I decided to do this work ourselves rather than hire the Polish crew, who had become somewhat difficult to deal with--and quite expensive. I was nervous about doing this, but have been starting to feel much more confident about what we have been able to accomplish ourselves. I guess this will be the ultimate test!

The reason we're going through all of this is to be able to remove a structural wall that's supporting the hip rafter at the midpoint. The hip rafter is the corner beam that all the other rafters are attached to - it's like the spine. In order to open up the living area and remove this final wall, we need to be able to compensate for the wall's support once it's gone. To do this, our engineer specified two heavy steel channels that will sandwich the original wooden beam. The steel will provide the necessary stiffness, but there has been a significant amount of grumbling from the guys that this is over-engineered. In this case I do agree with them, and I had tried to get the engineer to change the design, but he refused. So we were left without a choice, and we've had to build the bridge in the living room and will spend the next few days doing what will probably be the riskiest work of the entire project.

Removing the first few slates at the corner

Almost enough removed to start work on the steel

Cutting the post that supports the hip rafter!

The view from inside the flat

Separating the rafters from the hip rafter to make space for the steel

Inserting the 1st piece piece of steel

Getting it to fit - not much space to work with

The 1st piece of steel in place

Inserting the 2nd piece of steel

Setting the clips that will hold the steel in place

Both beams in place

Today we were lucky. Everything went much better than expected, and considering the risks involved, I'm feeling relieved and more confident that we can finish this phase without incident.