Aldergrove Roofing

08/16/2026

Hidden Gutter Drain Leak on a Coquitlam Tile Roof: Why the Drain Goes Over the Membrane

We got a call for an active drip on a tile roof in Coquitlam. The water was not coming through the tiles. It was running out of the hidden gutter, and when we got up there the cause was the drain.

Why a hidden gutter drain is worth getting right

A hidden gutter, also called a built-in or box gutter, is a trough built into the roof itself instead of hung off the fascia. On this house the concrete tile roof sheds into it, and the trough is lined with an EPDM rubber membrane. It looks good from the ground because there is no gutter hanging off the edge, but there is a trade-off. A hung gutter that fails drips down the outside of the house where you can see it. A hidden gutter that fails puts water into the roof.

How much trouble that causes depends on what is underneath. This gutter runs over an overhang, so the water found its way out under the overhang instead of into the house, and that is how the homeowner noticed it. That is the lucky version. Where there is no overhang, or where the hidden gutter runs above living space, the same failure puts water inside the building, and usually nobody finds out until there is a stain on a ceiling.

Either way, the whole system rests on two details: the seams and the drains. On this roof it was a drain.

The two inch drain as we found it, with caulking around the fl**ge doing a job it was never going to hold.

The drain was built in the wrong order

Here is how it had been done. The copper drain went down first. Caulking was applied on top of the copper fl**ge. Then the rubber membrane was laid over the caulking.

That seems reasonable if you think a roof works by being sealed up, but it ignores what rubber does. EPDM expands and contracts with temperature, every day of the year, and copper does not move with it. The only thing joining the two is a bead of caulking, and it gets worked back and forth until it lets go.

Once the membrane is unbonded from the fl**ge, water running down the gutter does not drop into the drain. It runs around the outside of the fl**ge and into the roof. We cut the membrane back to expose the fl**ge so we could pull the old drain out, and you can see how little of it was still stuck down.

Membrane cut back to expose the old fl**ge. The bond between the rubber and the copper had already let go.

Two inch out, three inch in

The old drain was a two inch. We put in a three inch. A hidden gutter collects everything the tile roof sheds, all of it funnelling down to one small opening, and a two inch outlet plugs up fast. A three inch takes a lot more debris before it blocks, which keeps the water moving through instead of backing up and spilling over the side of the gutter.

Most people assume the downspout has to be changed as well. It does not. A three inch drain fits a standard two by three downspout, so on most hidden gutters this upgrade can be done without touching the downspouts at all.

The old two inch drain beside the new three inch. The bigger outlet is far harder to block with debris.

How we rebuilt it

This repair lives or dies on the bond, which means it lives or dies on the prep. We cleaned the existing membrane thoroughly around the drain first. Glue on a dirty membrane is just a slower version of the same failure.

Then the new three inch drain was fastened down on top of the membrane. That is the change that matters. With the copper fl**ge sitting on top of the rubber, the fl**ge holds the membrane down. The old way asked a bead of caulking to do that job, and caulking is not a fastener.

The new three inch drain fastened down on top of the cleaned membrane, which is the correct order.

Next we brushed the proper bonding adhesive across the cleaned membrane and around the drain.

Bonding adhesive brushed out around the new drain, ready for the patch.

Last, the patch went over the top and lap sealant was run around every edge. The patch is rubber bonded to rubber, so it expands and contracts along with the membrane underneath it. Nothing is being pulled against something that will not move with it, and that is the whole reason the original detail failed and this one will not.

We use Elevate premium membranes for these patches. That is a commercial EPDM roof system. If a building owner trusts it to keep the water out of an entire commercial roof, it is more than good enough for a hidden gutter. Every patch we do carries a five year warranty.

The finished patch bonded over the drain, with lap sealant around all four edges.

What to watch for on your own hidden gutter

If your house has a hidden gutter, these are worth a look before the wet season:

Whether the drain is actually clear. These gutters are built on the rafters with almost no slope to them, so some standing water is normal and not a problem by itself. Water that never goes down is.

Debris piled up around the outlet, especially under overhanging trees.

Caulking visible around a drain fl**ge. Caulking is not what is supposed to be holding a drain in.

Any staining on the soffit, the fascia or a ceiling near the eaves.

While we were on this roof the homeowner had us upgrade the rest of the drains and seal the seams as well, which is the sensible way to handle it. If one drain was built this way, the others were built the same way on the same day by the same person.

Hidden gutter repair in Coquitlam

Hidden gutters are common on tile roofs across Coquitlam and the rest of the Lower Mainland, and the drains are the first thing we check when one of them leaks. If you have a drip you cannot trace, or you just want the drains and seams looked at before the rain sets in, we can take a look.

More on hidden and built-in gutter repair, on concrete tile roof repair, or see the roofing work we do in Coquitlam.

Full photos and details:

A drip on a Coquitlam tile roof traced to a hidden gutter drain installed under the EPDM membrane. See why that order fails and how we rebuilt it.

08/02/2026

This concrete tile roof in Langley had the old tiles removed, new sheathing installed, ice and water shield at the eaves, synthetic underlayment over the rest, and architectural asphalt shingles to finish.

Here is the part most people never get told: concrete tile sits on spaced boards, and asphalt shingles need a solid deck underneath. So going from tile to shingle means the whole roof gets new sheathing. It is not an upsell, it is what the job actually requires, and it is the line some quotes quietly leave out.

Got a tile roof you are worried about? We do concrete tile repair and full tile roof replacement across Langley, Abbotsford, Surrey, Vancouver and the Fraser Valley.

Call or text 778-389-5564
aldergroveroofing.ca

07/13/2026

Broken Roof Tile Replacement in Coquitlam: Why We Use Recycled Columbia Tiles

We got a leak call on a tile roof in Coquitlam. When we got up there, the cause was easy to find. One tile was broken, and someone had already tried to fix it by smearing caulking over the break. That is not a repair. Here is why, and how we actually fixed it.

A broken tile and a bead of caulking

We see this one a lot. It makes sense if you think a roof works by being sealed, but a tile roof does not work that way. Tile sheds water. Each tile carries water down to the one below it and out to the gutter. When a tile is broken, water goes through the break and gets under the tiles, where it soaks the underlayment and works its way inside. Caulking sitting on top of the break does not change where that water goes. It shrinks, it cracks, it lets go, and the leak comes right back. The only real fix for a broken tile is a new tile.

The broken tile as we found it. Someone had smeared caulking over the break, which does not stop the leak.

Taking out a broken tile without breaking three more

Tiles are not loose pieces sitting on the roof. They overlap and interlock with the tiles around them and they are fastened down, so you cannot just grab a broken one and pull it out. If you try, you will break the tiles beside it. We use pry bars to lift the tiles on each side, which frees the broken one up, and then it slides out. Slow and careful, and the surrounding tiles come through it just fine.

We lift the tiles on each side with pry bars so the broken one can slide out without damaging its neighbours.

The replacement, and why it is a recycled tile

Here is the part most people do not know. These are Columbia tiles, and they do not make them anymore. So when one breaks, there is no new tile to go buy. You cannot just drop in a modern tile either, because the profile will not match the tiles around it, and if the profile does not match then the water channels do not line up and you have just created a new leak.

So we use recycled tiles. When we re-roof a house that has a tile roof and the owner is switching to shingles, we save the good tiles. That gives us a stock of the old discontinued profiles, Columbia included, to pull from for repairs exactly like this one. The replacement drops in, the channels line up with its neighbours, and the roof works the way it was built to.

The replacement is a salvaged Columbia tile. They are not made anymore, so we keep recycled ones on hand for repairs.

Why this matters

A broken tile is a small repair if you do it right, and a leak that keeps coming back if you do not. Caulk is not a fix. Matching the tile is not optional. And if your roof is an older discontinued profile, you want a roofer who actually has the tiles, not one who tells you the whole roof has to go because they cannot find a match.

If you have a tile roof with a broken tile, or a leak you have been patching over, get it looked at properly. We keep salvaged tiles on hand for discontinued profiles, and we repair tile roofs across Greater Vancouver and serve Coquitlam and the surrounding area. You can also read about the hidden broken water channels we find on tile roofs. Call 778-389-5564 for a free estimate.

Full photos and details:

A caulked-over broken tile was leaking on a Coquitlam tile roof. See how we removed it properly and replaced it with a recycled Columbia tile.

07/12/2026

Electrical Mast Flashing Leak on a Tile Roof in Chilliwack

On a tile roof in Chilliwack, the leak was coming in around the electrical mast, the pipe that carries the power line up through the roof. When we got up there, the problem was easy to spot. The rubber boot around the mast was torn, and whoever installed it had used the wrong kind of flashing for a tile roof. Here is what was wrong and how we fixed it.

The problem

Two things had gone wrong. First, the rubber boot that seals against the mast had split and torn, which on its own lets water run straight down the pipe and into the house. Second, and this is the bigger issue, the flashing had a flat, solid fl**ge. Tile is not flat. It has a raised, wavy profile, so a flat fl**ge just sits up on the high points of the tile and leaves open gaps underneath along every channel. Water blowing across the roof runs right under it.

The old mast boot was torn, and its flat fl**ge sat up on the tiles instead of sealing to them, leaving gaps for water.

Why a flat fl**ge does not work on tile

On a smooth roof like asphalt shingle, a flat fl**ge lies down and seals fine. On tile it cannot. The fl**ge bridges from one high point to the next and never touches the low channels in between, so there is a permanent gap for water to get under. It might look sealed from a distance, but water follows those channels, and on a tile roof the channels are exactly where the water runs. The torn boot just made an already leaky detail worse.

The fix

We replaced the whole thing with a mast flashing made for tile. It has a larger, malleable fl**ge that we shaped down into the profile of the tiles, so it presses into the channels instead of bridging over them. That gives it full contact with the tile and a watertight seal all the way around, and the new boot grips the mast the way it should. Now water running down the tiles hits the flashing and is carried over the top of it, not under it.

The replacement has a larger fl**ge that we shaped into the profile of the tiles for a watertight seal.

Why it matters

Roof penetrations like electrical masts, plumbing stacks, and vents are the most common place a roof leaks, because they interrupt the smooth path water wants to take. On tile especially, the flashing has to match the shape of the tile or it will leak no matter how much sealant is smeared on it. Using the right part for the roof type is the whole job.

If you have a tile roof and you are seeing a leak near an electrical mast, vent, or pipe, it is worth getting the flashing looked at, because sealant alone will not fix the wrong fl**ge. We repair tile roofs across Greater Vancouver and serve Chilliwack and the surrounding area. You can also read why we replace roof vents on tile roofs with lead flashing. Call 778-389-5564 for a free estimate.

Full photos and details:

A tile roof in Chilliwack leaked at the electrical mast where a flat fl**ge could not seal to the tiles. See how the right conforming fl**ge fixed it.

07/12/2026

Hidden Tile Roof Leaks From a Broken Water Channel in Burnaby. This one is a good example of why a tile roof can leak even when it looks perfectly fine, not just from the ground but even when you are standing on it. We were on a tile roof in Burnaby chasing a leak, and every...

On a Burnaby tile roof the tiles looked fine, but a water channel broken under the overlap was leaking. See how these hidden tile leaks happen and how we find them.

03/07/2026

Tile roof repair in Burnaby, BC. Swapping out old plastic vents and replacing broken tiles that were causing leaks. Done right, the first time.
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02/25/2026

Our team specializes in concrete tile roof repairs, done right the first time. Don't let a small problem turn into a costly nightmare.
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