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Tamko Home Additions & ADU: The Miami Owner’s Guide
Mason Remodeling Co Miami installs Tamko-compatible home additions and ADU structures throughout Miami, with full build-outs typically running $53,100 to $153,400 depending on square footage, foundation work, and finish level. That’s a wide band, so let’s anchor it: a one-room bump-out in a Miami ranch starts around the low $50s, while a permitted two-story addition with a kitchenette pushes into the $150s. Most callers find out their existing Tamko addition is failing through water staining at the roofline seam, a door that suddenly won’t latch, or a floor that has started sloping toward the exterior wall.
What they’re actually seeing is the connection between the original structure and the addition starting to move independently, which is the most common failure point we repair in Miami’s limestone soil and hurricane-cycle humidity. The good news is that the damage is almost always confined to one identifiable joint, flashing run, or foundation edge, and that’s where the repair starts before any finish work happens.
Which Tamko Models This Applies To
Tamko’s residential building product lines carry several series designations depending on vintage, and the compatibility questions we hear most in Miami fall into two buckets. First, the framing and tie-in hardware used on pre-2015 Tamko addition kits versus the current riveted-connector specs. The older series used lighter-gauge steel connectors at the roof-to-wall intersection, and those are the ones that show corrosion first in Miami’s salt-heavy coastal air. Second, the flashing and underlayment family, where Tamko’s newer composite peel-and-stick membranes have a wider adhesion temperature range than the older granular-surfaced rolls.
Here’s the gotcha: Tamko addition kits are not all backward-compatible at the tie-in points. If you have an original-series kit from the mid-2000s, a current-generation connector plate will not line up with the old hole pattern without re-drilling, and re-drilling a load-bearing connector weakens it. We stock both OEM Tamko connector plates and engineered aftermarket equivalents from Simpson Strong-Tie that carry the same Miami-Dade NOA (Notice of Acceptance). For flashing, we carry the OEM Tamko product line because the adhesion chemistry is matched to the original underlayment. Mixing brands there is where Miami humidity creeps in and the warranty dies.
To identify your series before calling, look for the embossed code on the manufacturer sticker inside the addition’s main access panel or on the underside of the sill plate near the original house wall. It will read something like “TAMKO-ADD-S2” followed by a year. That code tells us more than any photo of the damage.
Styles & brands we work with
Signs Your Tamko Home Addition or ADU Is Failing
- A thin, horizontal crack running along the seam where the addition roof meets the original house wall. This is differential settlement: the addition’s slab or pier footing is moving at a different rate than the original foundation. Miami’s wet-dry soil cycles make this common after five to seven years.
- Doors inside the addition that bind at the top corner in summer and swing freely in winter. The door frame is racking as the addition’s floor joists swell and contract with Miami’s seasonal humidity. The frame wasn’t shimmed and sealed properly, and the gap opens at the header first.
- Daylight visible under the baseboard at the far exterior wall. The floor assembly has dropped, usually from a rotted rim joist where the original flashing was undercut or never sealed. In Miami, this rot starts at the lowest point of the wall, where wind-driven rain pools against the foundation edge.
- Soft spots in the floor at the midpoint of the addition, not at the edges. That’s not settlement; that’s a failed pier or a joist that has lost its bearing. On raised Miami additions, we find this often when galvanized hangers were used instead of stainless, and salt air ate them through.
- A musty smell after heavy Miami downpours, even with the AC running. The addition’s vapor barrier was not tied into the original building envelope. Humidity is entering through the crawlspace or the roofline gap and feeding mold inside the wall cavity.
Each of these has a defined repair path. None of them fix themselves.
See the difference
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After
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AfterReplacement Cost & What’s Included
For a Tamko addition or ADU repair and rebuild in Miami, you’re looking at these ranges based on how far the failure has progressed:
- Full addition or ADU construction (new build, permitted): $53,100 to $153,400
- Structural tie-in repair at the roof-to-wall seam (including flashing replacement): $4,720 to $11,800
- Floor joist or rim joist replacement with sistering: $3,540 to $10,030
- Full wall or roof component rebuild after water damage: $10,620 to $33,040
Every Mason Remodeling Co Miami project includes a written price before any work starts. That’s our policy, not a promotion. The written quote covers the parts, the labor, the disposal, the permit application (we pull permits ourselves), the inspection, and the final walkthrough. If we find hidden rot once a wall is open, we stop, show you what we found, and put the change in writing before touching anything else. No surprise invoices.
Your completed project is covered by our 365-Day Done Right Promise. If the work is not right within one year of completion, we make it right at no cost to you, including a free return visit if the repair or installation fails.
DIY or Call Us?
There are two or three things you can safely do yourself before picking up the phone. You can run a level across the floor at multiple points and note where the bubble sits. You can mark the existing crack with a pencil line and check whether it widens over a two-week period. You can photograph the manufacturer sticker inside the access panel so we know which Tamko series you have. Those save a visit and help us price the job accurately.
What you should not do is try to repair a structural tie-in yourself, open a wall to “take a look” at a sagging floor, or re-flash a roofline seam from a ladder. Any one of those can turn a $5,000 repair into a $50,000 rebuild, and a Miami roof in the summer is not the place to learn how flashing works. As Isaac Pruett puts it when a homeowner asks whether they should try the fix first: “Tell me what you need done. I’ll tell you what it costs and when it’s finished, and I’ll mean both.”
Call (850) 780-8123 and ask for a free estimate. We’ll come out, read the job, and give you a straight number.
FAQs
A correctly tied-in Tamko addition in Miami’s climate lasts 30 to 40 years on structure, with flashing and sealants needing replacement every 8 to 12 years due to UV and salt exposure. Call (850) 780-8123 if yours is showing signs sooner.
Yes, most Miami failed additions we see need repair at one connection point, not full replacement, as long as water intrusion hasn’t rotted more than a single joist bay. We’ll tell you where that line is once we open the wall and look.
A single tie-in repair takes two to four working days; a full permitted ADU build runs 10 to 18 weeks depending on Miami-Dade inspection scheduling and finish level. Written schedules are part of your quote.
We stock OEM Tamko flashing, connector plates, and underlayment for the most common Miami-series kits, and we source anything uncommon within 48 hours. You never need to order parts yourself.
If you’re in the middle of this exact problem in Miami, call (850) 780-8123 now and ask for a free estimate. A live person answers, and you’ll get a name and photo of who’s coming before the visit. We also work with KraftMaid, Cambria, and Silestone product lines on the finish side, so the whole project can be handled by one crew and one written quote.
Written by Isaac Pruett, Owner, Mason Remodeling Co Miami, serving Miami and nearby areas.
