Anyone else struggled to get decent mobile signal in a timber clad garden office?

Had this exact problem with my shepherd's hut build last spring. Timber cladding isn't the worst offender but once you add insulation batts, a vapour barrier, and internal lining boards you're effectively building a decent little Faraday cage.

What actually sorted it for me was a Cel-Fi GO repeater unit. Not cheap at around £500-600 but it's network-legal in the UK (important — a lot of the cheap Amazon boosters are not Ofcom compliant and technically illegal to operate). It pulls signal from outside via a donor antenna mounted on the roof, amplifies it, and rebroadcasts inside. Went from one bar of EE to solid 4G throughout.

A few things worth checking first though before spending money:

• Antenna placement matters enormously — even a few feet of height gain on the donor antenna can make a significant difference
• Which networks are actually available at your location? Mastdata and Ofcom's checker give different results; I'd check both
• Is it just voice/texts or data too? Sometimes a basic Wilson antenna pointed at the nearest mast solves it for pennies

Also worth noting that if you're running a Victron system with a GX device and want remote monitoring via VRM, poor signal kills that entirely. That was my actual motivation for fixing this properly rather than just living with it.

Curious whether others have gone down the repeater route or found alternative solutions — particularly anyone in areas where even the donor signal outside is borderline.

CamperRachel | 847 posts | ⚡ Solar Enthusiast

@LiamFrost70 yes, absolutely had this with my converted garden office last year! The vapour barrier was the main culprit for me - once I swapped to a foil-faced one for better thermal performance it basically killed my signal entirely.

What worked brilliantly was running a short length of coax through the wall with a proper outdoor antenna on the roof, feeding into a small signal booster inside. Picked up a Three repeater kit for around £80 and it transformed things. Dead simple to fit and no planning headaches.

Worth checking whether your network provider offers a Wi-Fi calling option as a stopgap too - I used that initially before sorting the antenna properly. EE were surprisingly helpful when I explained the situation.

SussexWanderer | 1,203 posts | 🔋 Off-Grid Convert

Worth mentioning that the orientation of your building matters more than people realise. My larch-clad office faces away from the nearest mast and I was getting one bar at best. Fitted a Cel-Fi GO mobile repeater last autumn and it's been transformative — pulls signal from outside via a donor antenna on the roof and rebroadcasts inside. Completely passive from a planning perspective too, no structural alterations needed.

One thing I'd add for anyone running solar out there: the repeater itself draws minimal power, around 2W typically, so it won't make a dent in your battery budget. Check ofcom.gov.uk before buying though — certain boosters aren't legal for use here and you want to make sure you're getting something network-approved. @LiamFrost70 which network are you on? Makes a difference to which unit suits you best.

RetiredEngineer61 | 412 posts | 🔧 Practical Tinkerer

Curious whether anyone's tried an external antenna mounted on the fascia board feeding a signal booster inside? I've got a similar layered wall construction in my static caravan — foil-backed insulation is the real culprit in my experience, worse than timber by a long way.

Was looking at the SureCall or Cel-Fi GO units — anyone had hands-on experience with those in the UK? I understand Ofcom regulations mean not all boosters sold internationally are actually legal here, which narrows the options somewhat.

@SussexWanderer — good point on orientation. Would that also affect an external antenna placement, or is the booster amplification enough to compensate for a slightly suboptimal direction?

SmartSolarNerd | 156 posts | 🔋 Battery Nerd

Does anyone know if running a lot of 12V cabling near the walls makes interference worse? Got a static caravan setup with Victron kit and a fair bit of wiring running around the perimeter — wondering if that's adding to my signal issues or if I'm barking up the wrong tree entirely.

Also — @RetiredEngineer61 — the external antenna idea, is that a standard coax run through the wall to an indoor booster unit? What sort of brands are people actually using for that in the UK? Seen some cheap stuff on Amazon but no idea if it's worth bothering with or if you need to spend proper money on it.

My signal outside the caravan is decent enough, it's specifically inside where it dies.