Let The Sun Shine In (Again) - Replacing A Shower Skylight - Part 1

Damage

    During the last "superstorm," my shower skylight took a hit from a wind propelled chunk of tree. It smashed straight through the skylight and was found on the bottom of my shower stall. The skylight, which was original, was already brittle and cracking. I had been patching it up for quite a while anyway. This was the final nail in it's coffin. Not the best way to stop procrastinating, but it works! I really just wanted to replace it with another same-size and type. Unfortunately, they no longer exist. I had to measure and have a dome-style one manufactured. Most of you will simply have to order a stock size and then install it.

After The Winter

Since this happened over the winter, there was no way I would be able to replace it immediately. For a quick fix, I was given a plastic corrugated sign from some politician's last campaign and it cut up nicely to size. I used heavy tape to hold it on and plastic packing tape to seal around the edges. This made for a watertight temporary fix. I wouldn't recommend driving down the road at 60MPH with it, but for the winter driveway storage it was fine. During this time I ordered the custom skylight. Once warmer weather arrived it was time to get to work. The concept of this is straightforward, but you really don't know what you are getting into until the old one is removed.

Eternabond Tape Removal

First, we took off the "patch" and then began to remove the Eternabond 4 inch tape that surrounded the old skylight on all four sides. This is NO fun at all. I thought I'd be able to use some thin piano wire and two blocks of wood to get under the tape and cut the adhesive. This didn't work as the skylight itself is in the way. Instead we used a razor knife, to cut the adhesive while pulling up on the tape itself. This works well, and since the remaing adhesive is REALLY sticky, it will form a base for the new tape later on. This stuff sticks to everything and every body part that gets near it.

Tape Adhesive Is A Stubborn Thing

 Sometimes I thought I could hear it laughing at me. OK, so it was sunny and hot..maybe I was hearing things? It went slow, but predictably. We cut through all of the adhesive and removed all the tape. Since a good portion of the tape was on the "lip" of the old skylight, final cleanup past the edges wasn't too bad. I went down into the shower and had a friend pull up from the edges. It was a bit of a struggle, but the skylight mainly pulled free without too much of a fuss. There was quite a bit of edge caulk, likely a whole bunch of previous leak repairs.

Pooling Water Formed At the Top Left In A Trough

Almost all of the screw holes had cracks and had been filled with silicone caulking and/or some other kind of sealant. Pealing this off was the most difficult part of the job. It took a lot of scraping with a putty knife to remove fully. Even so, I am SURE there was some remaining on the fiberglass roof.

You know, it's very odd to stare down through the open roof into your bathroom. I'm not sure why, but it is.

All of the fiberglass was intact, so no repairs were needed there..WHEW!

Leveling Shims In Place

Next, I had to figure out how to level the roof and get some kind of a wood backing for the screws to go into. It seems that the roof wasn't supported in many spots and the sag had led to water pooling around the skylight. This, in turn, led to water getting in and probably the excessive use of caulk to try and fix it over the years. A combination of wood and composite shims were used to level out the edges so the slope would naturally drain off the roof instead of into the skylight.

Fiberglass Insulation Under Roof 

While working on the under-roof support, it became obvious that many of the original screw locations had nothing underneath. The screws simply went into the fiberglass and that was it. Not very secure at all!

The fiberglass insulation was a bit ratty as well, but I'd be replacing/supplementing it with expanding spray foam as well.

The rough edges of the fiberglass cutout for the skylight wouldn't matter as they are hidden by the skylight itself.

Finished Backing For New Screws AND Level Roof

Several pieces of 1"x 2" pieces were cut to fill the gaps under the fiberglass and provide a base for the new screws. A few of the original screws were used in the original holes to keep the wood in place while we worked. These would be removed before the new skylight was placed into position. Once all of the wood platforms were cut and in place, and BEFORE the spray foam inserted into the gaps, we test fit the new skylight.

Not good.

It didn't fit.

It seemed that the custom ordered skylight bubble section was ever so slightly smaller than the old square cross section one and wouldn't completely surround the shower enclosure and therefore would not lie flat!

What Now?

Tune in next week for Part 2, where we'll talk about how to fix this kind of problem "mid-job" and still have a good result that will be secure, leak-free and functional.

See Part 2 of this article.

Be Seeing You, Down The Road,

Rich "The Wanderman"
www.thewanderman.com