Shielding phone tower radiation

21-Sep-2017

The following is a report on the partial shielding of a brick home from mobile phone tower and wifi from a customer.

Background

This brief report concerns how a lay person (science trained), with assistance of a brick layer, painter and electrician, substantially reduced EMR levels in the home by step-wise modifications over a three-month period.

My emr sensitivity is from 0.05 volts per metre and above, with symptoms of dizziness, balance disturbance, brain fog, sometimes nausea and nose bleeds, with symptoms depending on the length of exposure, the peak electric field flux and the energy flux.

I have ME/CFS and some chemical sensitivity all of which may contribute. I have recently minimised my exposures by curtailing activities, as a trial to see how much my health may improve. The recent activation of 4G is responsible for increases from 2 to 8 times in electric field flux in the areas I was visiting (already a selected list of places

The activation of a new mobile phone tower 420 metres away was the spur for the home shielding project. The one level brick home is basically L-shaped with the main spine running from east to west, and the bottom of the L running S-N. There was already aluminium roof insulation laid over ceiling joists, from 2009. 

The tower, its orientation to the house, and surrounding factors that affected the signals

The mobile phone tower is a 850MGHz (WCDMA) / 700 MGHz (LTE)/ 1800 MGHz (LTE) tower in a residential area. A TV aerial specialist who visited the home was getting a 4G signal on his spectrum analyser, though it is possible not all frequencies from the tower are currently being transmitted. He replaced the TV aerial with another that did not pull in the 4G signal to the house (just in case this had any influences via the internal cable or produced effects on TV reception further down the track). He took my Acoustimeter onto the roof and confirmed that as I thought, the main exposure was coming from the west. On the roof he measured 500 microwatts per square meter and 0.5 to 0.7 volts per meter in the period of his brief recording.

The lobes of likely maximum emission from the tower were north east and south west from the property – that is, the home doesn't lie below the directions of likely maximum emissions. The maximum reading (exterior) was at the rear (west) of the property, peaked at 1 volt/meter (chest height), and EMR was significantly impacting the whole of the west wall, probably with the electric field propagated in the horizontal plane. There was also some impact on the north section (possibly by diffraction of the signal around the corner), but the electric field fell substantially along the first six metres of that north wall so there was little tower impact on the other (north-south) spine of the house (its front). 

Factors protecting the north wall from higher EMR may have been:

1. the house spine running inward from the west is parallel to another similar brick house that is 12 metres away from the north wall, but 1.2 metres higher in elevation and so may be shielding my house from the north.

2. a densely foliaged lillypilly tree was on the north-west corner of the yard about 8 metres away, and there is also a western fence, and a 1.8m high brick wall enclosing most of the courtyard out from the north wall.

What were the internal readings of EMR?

Acoustimeter

Within the house the readings in the two rooms on the western endwere significantly affected and peaked at 0.3 volts per metre, and 0.6 volts per metre, respectively, at fairly low energy density – not exceeding around 8 microwatts per square metre.The noise on the Acoustimeter indicated mobile phone tower EMR. 

The readings were higher in the room without a window facing west. As shielding proceeded it was found that instead of 3 minor wifi signals (in 2012) near the rear of the home, there were now 5 including one that identified (on a friend's mobile phone) as 5 GHz wifi, and some of these were adding to the readings in this room via its south-facing window.

Other rooms in the house were being affected to varying extents primarily by wifi at readings from 0.07 to 0.19 volts per metre. There were two skylights, one of which was elevated to 0.06 volts per metre.  

De Tekta readings

The household power supply with everything disconnected had a maximum of 1150 millivolts and a minimum of around 400 millivolts at various locations in the house. The maximums were not in the rooms of highest Acoustimeter readings. One filter reduced the levels in the computer room (hardwired internet) to below 100 millivolt in that location and the other locations were not worried about too much but two dimmer switches were removed as they seemed to be contributing around 15% elevation to the deTekta readings.

The higher frequency noise on the power supply in the house included a radio station in the 600 KHz range – this was quite clearly identifiable with the deTekta meter. 

PF5 readings

These were elevated on a number of walls – 100 to 150 to 200 volts per metre electric field flux. The affected walls were not necessarily those with the most power points or light switches and seemed to be mainly on walls running under the ridges of the roof line of the house. It wasn't believed there were wiring errors and the electrician checked the roof space. The wiring type is tree and branch not radial and there were no dangling wires.

The elevated PF5 readings are not explained at this time, but could be the consequence of interaction of the tower EMR with the aluminium insulation laid across the ceiling joists. This is just a thought. However, the aluminium insulation seems beneficial – see later. 

Planning shielding measures – where, and the considerations

The objective was to reduce to 0.02 to 0.03 volts per meter the electric field flux from tower and wifi, though it was considered acceptable to have some higher values in limited areas where little time was spent.

The west wall is a high peaked wall without eaves and the roof there faces north and south not west. The two rooms adjacent this wall were the ones mainly affected by tower EMR penetration. The wifi was mainly coming in through the windows of rooms from a variety of directions. 

Considerations:

1. The house has white tiles and was recently painted with low VOC paint without preservatives prior to activation of the tower. It was not desirable to paint again internally.

2. Also there have been some reports on line of people not finding total internal painting/ shielding “right” for them – for whatever reasons - and I felt my sensitivities and the deTekta readings gave another reason why it could be preferable to shield the house partially externally rather than internally which would need grounding of internal shielded painted walls to the household power supply.

3. So, in my particular case, I decided to try shielding first the west wall externally with HSF54 paint with AF3 fibre additive, and to use LX window film on the necessary windows and internal surface of the bottom plastic plates of the skylights. An ensuite bathroom window with irregular opaque glass couldn't have film and so a Naturelle curtain was used there (that bathroom shower isn't used so there wasn't a humidity problem; the partial penetration of EMR to the other bathroom was ignored). 

Pre Planning

A check was made that the frequencies to be screened against would be blocked adequately by all materials used. The pressure sensitive version of Alpha (LX 70 window film) was chosen in the first round of treatments as the dry adhesive form would not have adhered to the plastic of the skylight bottom panels, only to glass.

Unfortunately, the Boral Ascot bricks of the house are bevelled and laid with raked joints (8 mm deep). Though not considered a porous type of brick, all brick is porous to some extent, and additionally this brick has surface bursts of black silica-based glass plus textural variations – not ideal for shielding projects!

For these reasons it was decided to bag the west facing brick wall, and to use the GK5 sealer recommended by the Yshield Germany website.

The west wall (28 square metres) has 2 expansion joints so 3 GE grounding plates, cables and GR-100 grounding rods were also obtained for that wall. 

The Work Scheduled and Started – the Sequence of Events

1. Chosen windows were treated with Alpha film, allowing 1 week between installation and edge sealing with the silicone recommended by the manufacturer. The Naturelle curtain was installed on one (unused) bathroom window.

2. Electrician removed one light fitting, detached an air conditioning duct and swung out an air conditioner base unit on the west wall.

3. Bagging of the west wall with cement-sand-Bondcrete to reduce the depth of the joints, and help later adhesion. The bricklayer also prepared the locations for the grounding plates and removed clay pavers in channels from the wall to the nearby garden edge, to allow for the grounding cables. The bagged wall was cured with twice daily hosing, and left overall 20 days.

4. The electrician returned to put in the plastic rawl plugs for both the grounding plates (GE) and for the attachment of the plastic conduit that would protect the three GW (5 metre) grounding cables leading to three grounding rods (GR-100). The rawl plugs were slightly proud of the surface so as to not be “lost” in the HSF54 application.

5. Painting began on day 20 after commencement of bagging, wall being considered dry enough.

a. First the sealer GK5 was applied. It was left to dry 48 hours (24 would probably have been enough).

b. The first coat of HSF54 with fibre additive AF3 (stirred by electric stirrer well first) went on via 20 mm (used, but still “fluffy”) roller – this size roller exceeds what the manufacturer recommends. It was still quite a job for the painter – it required considerable muscle as he worked mainly from ground level with an extended handle to the roller, and had to cope with indentations of joints of 2 mm in many places. Anyway, the skill of the master painter saved the day – a huge reduction in EMR with the first coat of HSF54 once dry, as hoped for – very pleasing.

No areas of strong signal seemed to be coming internally through the west wall, but a second coat of HSF54 was applied 2 days later. It went on more easily for the painter and seemed to cover significantly greater area per square metre. 

Recommendations from the above experience:

1. The bagging job should aim to reduce surface irregularity to the maximum amount possible

2. Do stress to the painter the importance of applying the first coat of HSF54 thickly. We ensured a whole 5 litre container was used for the 28 square metres, and were prepared to open the second container if required – so did use very nearly 1 litre per 5 square metres as recommended by manufacturer.

3. Do wait 48 hours (or longer) between coats of HSF54. The manufacturers say it is dry after 24 to 48 hours but cures in 7 days; I found that in external application (though fairly rapidly touch dry in our climate) as it cures it can retract a little (it seems) and so reveal spots of weakness that otherwise might not be detected and treated with attention if the second coat was applied too quickly over the first. This recommendation is likely to be particularly important if brush application is used – as was done partially on the north wall (see later).

3. Consider beforehand what you will do if signal is found to be coming in from additional areas externally once the job is started and partially completed.

4. With skylights, undetectable irregularity to the plastic surface, the particular plastic or its ageing may mean that even using the pressure sensitive version of Alpha window film there may be some difference in appearance when viewed from below on an angle – this happened with one of the two skylights. 

Assessing and Completing the Final Stages of the Work

Although only half a container of HSF54 was used for the application of the second coat, compared to the full 5 lites for the first coat, the west wall seemed well protected from EMR when measured with Acoustimeter inside. 

On an impulse, because I also had some sealer left (though not enough), I decided to paint the first seven square metres (approx) of the north face of the brick wall, even though it had not been bagged.

I decided I could live with the look of a painted but un-bagged section of wall, and that so could any future purchaser of the house, given the objective and the prevalence everywhere of EMR problems these days. The inducement was the thought that I could further reduce the penetration through that wall. Though it was at fairly low levels (0.05 to 0.07 volts per meter) starting from hip height internally, the tops of that north wall above head height did peak still at 0.15 volts per metre at some spots. These penetrations did not reach the areas of the room that were most used, but the success of the west wall treatment spurred me on. 

I had to be the painter – my painter was interleaving my job with another because of the wait times needed between coats, and was not due to return till the final coat of Dulux Weathershield was to be applied. So I had the experience of painting all the deep joints first with teaspoonful amounts of black paint and a tiny brush, to get into the crevices! (The painter did roughly roll one coat over the face of the bricks just before he left, but the rest was up to me.)

I had limited time - all the painting had to be completed on this north section of wall before the imminent arrival of the electrician who would test before he completed the grounding of the west wall.

When I had “done my best” with a combination of one and two coated areas of HSF54, the electrician's testing on this north wall showed that bagging really would have been preferable, as the ohm meter (unlike on the 2-coat finished west wall) showed many irregularities in readings, even though the Acoustimeter had shown moderate success in reducing EMR internally, even with my unskilled efforts. Around 40 readings were taken on the north wall by electrician ohm meter while I watched and noted, which allowed me to see the areas I had to concentrate on, for the second coat. 

I relied on my Acoustimeter to guide the application of this second coat and was rewarded with a reduction to 0.02 to 0.03 for areas of the wall up to 1.8 metres (corresponding to the top course of exterior brick). However, the room inside, being higher than the brick outside, still had some higher levels – up to 0.15 volts per metre at times – at the very top of the interior wall and across close to the ceiling for a distance of 0.3 to 1 metre into the room at various times of the day. 

Pondering further

I didn't want to paint internally. I had either to put up with the small penetration in areas that didn't really affect me, or try something extra.

Two thoughts came to mind:

1. Maybe I should paint the guttering (I thought also of a narrow section of roof as well, but discarded that idea).

2. Perhaps my aluminium insulation in the roof cavity needed to be added to – perhaps it wasn't out to the edges of the room. 

The value of a helpful electrician

My electrician was to return to replace the north wall light and the air conditioner base unit plus its ducting so the painter could apply the Dulux Weathershield cover paint.

Rummaging in my “throw nothing away” cupboard, I found a five metre length of Silver Wrap (used in building water proofing/ heat transfer prevention in walls sometimes).

Though the likely blocking effect might be sub-optimal (given the product), as a trial I asked my electrician to go up into the roof cavity with it, and use it doubled over at the top of that north facing wall close to the eaves and guttering, fixing it in place as he felt might work, to achieve our aim of reducing horizontal penetration of EMR above the brickwork. He concentrated on getting it as close to the north wall edge as possible, and also wrapped upwards to the rafters somewhat, doing a bit of cutting and attaching.

Amazing – lowered the penetration of the signal substantially (achieved the 0.02 to 0.03 volts per metre everywhere except in a few limited locations of occasionally up to 0.09; especially such peaks seem to occur when traffic is going home late afternoon, which seems to cause higher signal.

More of the same can now be done in the roof space in future if needed, with a better aluminium product. 

****Thanks to EMR Australia and my cast of trusty tradesmen, all of whom enjoyed finding out new things and are themselves now taking increased EMR precautions. I am grateful that I found tradesmen prepared to try something new and do well at it. *** It is important, if you are not “handy” yourself (as I am not) that your tradesmen are both ethical but also happy to work on a flexible quoting situation, as it can't always be foreseen by them how much time will be needed for such “new” types of work and they do need reassurance that their labours will be paid for appropriately. It's a two way street, isn't it. :-)  M.S.

 


 

< back to News

EMR Australia © 2017. All Rights Reserved. Terms & Conditions | Privacy | Sitemap | Adobe Business Catalyst Sydney