Addition of loft bedroom - Post #2

As promised here is an update on the loft reno project. In the initial post I outlined the rough plan of the project. In this second post some nasty stuff found in the area and a little about the base structure.

Unfortunately I don't have a good image of the wall between the house and the garage loft but what the previous owners had done was a definite no no.

To help insulate between the cold space in the loft and the adjoining bedroom they had added insulation to the wall, this in itself isn't such a big issue but to hold the fibre insulation to the wall they had made two major mistakes. Firstly they had stapled the insulation to the wall, severely compressing it making it effectively useless and secondly to help stop drafts, I assume, they had stapled over that sheets of thin plastic. In addition to using the pink insulation they had nailed some old suspended ceiling tiles. Not the greatest plan but what makes the whole thing a real problem was the tumble dryer exhaust. This was vented straight into the loft space which as you can work out pushed, over time, many gallons of warm moist air into a super cold area during the winter. And as I am sure you can guess there was a build up of mold, seen in this second image.

So the first part of this project was to have a damn good clean up to remove all the old, now damp insulation and soggy, mold invested ceiling tiles. Always take care with mold, seek advise if your not sure as it can be dangerous. My loft was well ventilated and with a mask and gloves I very carefully placed all the contaminated pieces in large plastic bags for disposal.

After the clean up I was able to start structuring the floor. Thankfully when the house was built the original owners specified the structure to be strong enough to support a second floor addition. The steel RSJ ("I Beam") was significant in size. The existing floor / ceiling was made from 2x6 joists, obviously these would not support a new floor and they would have to be strengthened. Based on the various structure guides on the Internet the addition of 2x8 would be strong enough.

I decided to go with 2x10 joists, these were glued and nailed to the original 2x6 joists and would give ample strength. The reason for going stronger than code was two fold, firstly I always like to make sure that the floor will not "bounce" with kids its always a good idea, and stronger is always better. Secondly to tie in with the height of the existing second floor 2x10 would allow an almost perfect height match.

In the next two images you can see a few of the joists added and the start of the insulation. Getting these 2x10 (16ft long) pieces of lumber into the loft space was hard work, there was very little space to move and you have to be very careful not to drop them onto the ceiling when putting them in place as they could easily fall through and end up in the garage. In total I used 22 joists, this part of the project was quite challenging more for the physical aspect than the technical difficulty. One thing to bear in mind when laying joists is the natural bend in all lengths of lumber. Firstly you should always have the bow facing upwards, over time they will tend to settle and if the bow is upwards they tend to settle to being straight.

Another big tip is to have them placed in order of bow, to make sure that the joists of equal bow were next to each other I stacked them on top of each other in order to make sure that my floor wasn't up and down across its width. This may sound like overkill but when I measured the difference in bow from the best to the worst joist was over 1/2 inch. If the worst was placed adjacent to the best floor would feel very uneven, by having them staged removes any gross changes in height.

In the next post starting the knee walls.

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